1
|
Jiang L, Zhang L, Shu Y, Zhang Y, Gao L, Qiu S, Zhang W, Dai W, Chen S, Huang Y, Liu Y. Deciphering the role of Enterococcus faecium cytidine deaminase in gemcitabine resistance of gallbladder cancer. J Biol Chem 2024; 300:107171. [PMID: 38492776 PMCID: PMC11007441 DOI: 10.1016/j.jbc.2024.107171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/18/2024] Open
Abstract
Gemcitabine-based chemotherapy is a cornerstone of standard care for gallbladder cancer (GBC) treatment. Still, drug resistance remains a significant challenge, influenced by factors such as tumor-associated microbiota impacting drug concentrations within tumors. Enterococcus faecium, a member of tumor-associated microbiota, was notably enriched in the GBC patient cluster. In this study, we investigated the biochemical characteristics, catalytic activity, and kinetics of the cytidine deaminase of E. faecium (EfCDA). EfCDA showed the ability to convert gemcitabine to its metabolite 2',2'-difluorodeoxyuridine. Both EfCDA and E. faecium can induce gemcitabine resistance in GBC cells. Moreover, we determined the crystal structure of EfCDA, in its apo form and in complex with 2', 2'-difluorodeoxyuridine at high resolution. Mutation of key residues abolished the catalytic activity of EfCDA and reduced the gemcitabine resistance in GBC cells. Our findings provide structural insights into the molecular basis for recognizing gemcitabine metabolite by a bacteria CDA protein and may provide potential strategies to combat cancer drug resistance and improve the efficacy of gemcitabine-based chemotherapy in GBC treatment.
Collapse
Affiliation(s)
- Lin Jiang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China; Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lingxiao Zhang
- Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yijun Shu
- Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuhan Zhang
- Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lili Gao
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Shimei Qiu
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Wenhua Zhang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Wenting Dai
- Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shili Chen
- Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Ying Huang
- Department of General Surgery, Shanghai Research Center of Biliary Tract Disease, Shanghai Key Laboratory of Biliary Tract Disease Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Yingbin Liu
- Department of Biliary-Pancreatic Surgery, Shanghai Key Laboratory for Cancer Systems Regulation and Clinical Translation, State Key Laboratory of Systems Medicine for Cancer, Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| |
Collapse
|
2
|
Toma-Fukai S, Sawada Y, Maeda A, Shimizu H, Shikanai T, Takenaka M, Shimizu T. Structural insight into the activation of an Arabidopsis organellar C-to-U RNA editing enzyme by active site complementation. THE PLANT CELL 2023; 35:1888-1900. [PMID: 36342219 PMCID: PMC10226597 DOI: 10.1093/plcell/koac318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/05/2022] [Indexed: 05/30/2023]
Abstract
RNA-binding pentatricopeptide repeat (PPR) proteins catalyze hundreds of cytidine to uridine RNA editing events in plant organelles; these editing events are essential for proper gene expression. More than half of the PPR-type RNA editing factors, however, lack the DYW cytidine deaminase domain. Genetic analyses have suggested that their cytidine deaminase activity arises by association with a family of DYW1-like proteins that contain an N-terminally truncated DYW domain, but their molecular mechanism has been unclear. Here, we report the crystal structure of the Arabidopsis thaliana DYW1 deaminase domain at 1.8 Å resolution. DYW1 has a cytidine deaminase fold lacking the PG box. The internal insertion within the deaminase fold shows an α-helical fold instead of the β-finger reported for the gating domain of the A. thaliana ORGANELLE TRANSCRIPT PROCESSING 86. The substrate-binding pocket is incompletely formed and appears to be complemented in the complex by the E2 domain and the PG box of the interacting PPR protein. In vivo RNA editing assays corroborate the activation model for DYW1 deaminase. Our study demonstrates the common activation mechanism of the DYW1-like proteins by molecular complementation of the DYW domain and reconstitution of the substrate-binding pocket.
Collapse
Affiliation(s)
- Sachiko Toma-Fukai
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuto Sawada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ayako Maeda
- Department of Botany, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Hikaru Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Mizuki Takenaka
- Department of Botany, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
3
|
Bao Q, Zhou J. Various strategies for developing APOBEC3G protectors to circumvent human immunodeficiency virus type 1. Eur J Med Chem 2023; 250:115188. [PMID: 36773550 DOI: 10.1016/j.ejmech.2023.115188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/18/2023] [Accepted: 02/04/2023] [Indexed: 02/09/2023]
Abstract
Host restriction factor APOBEC3G (A3G) efficiently restricts Vif-deficient HIV-1 by being packaged with progeny virions and causing the G to A mutation during HIV-1 viral DNA synthesis as the progeny virus infects new cells. HIV-1 expresses Vif protein to resist the activity of A3G by mediating A3G degradation. This process requires the self-association of Vif in concert with A3G proteins, protein chaperones, and factors of the ubiquitination machinery, which are potential targets to discover novel anti-HIV drugs. This review will describe compounds that have been reported so far to inhibit viral replication of HIV-1 by protecting A3G from Vif-mediated degradation.
Collapse
Affiliation(s)
- Qiqi Bao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China; Drug Development and Innovation Center, College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China
| | - Jinming Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China; Drug Development and Innovation Center, College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, PR China.
| |
Collapse
|
4
|
Li G, Cheng Y, Li Y, Ma H, Pu Z, Li S, Zhao Y, Huang X, Yao Y. A novel base editor SpRY-ABE8e F148A mediates efficient A-to-G base editing with a reduced off-target effect. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 31:78-87. [PMID: 36618266 PMCID: PMC9804010 DOI: 10.1016/j.omtn.2022.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Adenine base editors (ABEs) can mediate two transition mutations, A-to-G and T-to-C, which are suitable for repairing G·C-to-T·A pathogenic variants, the most significant human pathogenic variant. By combining the protospacer adjacent motif (PAM)less SpRY nuclease with F148A-mutated TadA∗8e deaminase, we developed a new editor, SpRY-ABE8eF148A, in this study, which has narrowed the editing range and enhanced A-to-G editing efficiency in most sites with NR/YN PAMs. Furthermore, compared with SpRY-ABE8e, SpRY-ABE8eF148A significantly decreased the RNA off-target effect. Therefore, this engineered base editor, SpRY-ABE8eF148A, expanded the editing scope and improved the editing precision for G·C-to-T·A pathogenic variants. Besides, we established a bioinformatics tool, adenine base-repairing sgRNA database of pathogenic variant (ARDPM), to facilitate the development of precise editors.
Collapse
Affiliation(s)
- Guo Li
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Yaxian Cheng
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Yeqiu Li
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China
| | - Hongru Ma
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zhongji Pu
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Sa Li
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yiqiang Zhao
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Xingxu Huang
- Zhejiang Lab, Hangzhou, Zhejiang 311121, China,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Yuan Yao
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China,Corresponding author Yuan Yao, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China.
| |
Collapse
|
5
|
Maiti A, Hedger AK, Myint W, Balachandran V, Watts JK, Schiffer CA, Matsuo H. Structure of the catalytically active APOBEC3G bound to a DNA oligonucleotide inhibitor reveals tetrahedral geometry of the transition state. Nat Commun 2022; 13:7117. [PMID: 36402773 PMCID: PMC9675756 DOI: 10.1038/s41467-022-34752-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/04/2022] [Indexed: 11/21/2022] Open
Abstract
APOBEC3 proteins (A3s) are enzymes that catalyze the deamination of cytidine to uridine in single-stranded DNA (ssDNA) substrates, thus playing a key role in innate antiviral immunity. However, the APOBEC3 family has also been linked to many mutational signatures in cancer cells, which has led to an intense interest to develop inhibitors of A3's catalytic activity as therapeutics as well as tools to study A3's biochemistry, structure, and cellular function. Recent studies have shown that ssDNA containing 2'-deoxy-zebularine (dZ-ssDNA) is an inhibitor of A3s such as A3A, A3B, and A3G, although the atomic determinants of this activity have remained unknown. To fill this knowledge gap, we determined a 1.5 Å resolution structure of a dZ-ssDNA inhibitor bound to active A3G. The crystal structure revealed that the activated dZ-H2O mimics the transition state by coordinating the active site Zn2+ and engaging in additional stabilizing interactions, such as the one with the catalytic residue E259. Therefore, this structure allowed us to capture a snapshot of the A3's transition state and suggests that developing transition-state mimicking inhibitors may provide a new opportunity to design more targeted molecules for A3s in the future.
Collapse
Affiliation(s)
- Atanu Maiti
- grid.418021.e0000 0004 0535 8394Cancer Innovation Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD USA
| | - Adam K. Hedger
- grid.168645.80000 0001 0742 0364Institute for Drug Resistance, University of Massachusetts Chan Medical School, Worcester, MA USA ,grid.168645.80000 0001 0742 0364RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA USA ,grid.168645.80000 0001 0742 0364Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA USA
| | - Wazo Myint
- grid.418021.e0000 0004 0535 8394Cancer Innovation Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD USA
| | - Vanivilasini Balachandran
- grid.418021.e0000 0004 0535 8394Cancer Innovation Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD USA
| | - Jonathan K. Watts
- grid.168645.80000 0001 0742 0364RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA USA ,grid.168645.80000 0001 0742 0364Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA USA
| | - Celia A. Schiffer
- grid.168645.80000 0001 0742 0364Institute for Drug Resistance, University of Massachusetts Chan Medical School, Worcester, MA USA ,grid.168645.80000 0001 0742 0364Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA USA
| | - Hiroshi Matsuo
- grid.418021.e0000 0004 0535 8394Cancer Innovation Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD USA
| |
Collapse
|
6
|
Chen Z, Liu X, Zhao P, Li C, Wang Y, Li F, Akutsu T, Bain C, Gasser RB, Li J, Yang Z, Gao X, Kurgan L, Song J. iFeatureOmega: an integrative platform for engineering, visualization and analysis of features from molecular sequences, structural and ligand data sets. Nucleic Acids Res 2022; 50:W434-W447. [PMID: 35524557 PMCID: PMC9252729 DOI: 10.1093/nar/gkac351] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/22/2022] [Accepted: 04/25/2022] [Indexed: 01/07/2023] Open
Abstract
The rapid accumulation of molecular data motivates development of innovative approaches to computationally characterize sequences, structures and functions of biological and chemical molecules in an efficient, accessible and accurate manner. Notwithstanding several computational tools that characterize protein or nucleic acids data, there are no one-stop computational toolkits that comprehensively characterize a wide range of biomolecules. We address this vital need by developing a holistic platform that generates features from sequence and structural data for a diverse collection of molecule types. Our freely available and easy-to-use iFeatureOmega platform generates, analyzes and visualizes 189 representations for biological sequences, structures and ligands. To the best of our knowledge, iFeatureOmega provides the largest scope when directly compared to the current solutions, in terms of the number of feature extraction and analysis approaches and coverage of different molecules. We release three versions of iFeatureOmega including a webserver, command line interface and graphical interface to satisfy needs of experienced bioinformaticians and less computer-savvy biologists and biochemists. With the assistance of iFeatureOmega, users can encode their molecular data into representations that facilitate construction of predictive models and analytical studies. We highlight benefits of iFeatureOmega based on three research applications, demonstrating how it can be used to accelerate and streamline research in bioinformatics, computational biology, and cheminformatics areas. The iFeatureOmega webserver is freely available at http://ifeatureomega.erc.monash.edu and the standalone versions can be downloaded from https://github.com/Superzchen/iFeatureOmega-GUI/ and https://github.com/Superzchen/iFeatureOmega-CLI/.
Collapse
Affiliation(s)
- Zhen Chen
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China.,Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou 450046, China
| | - Xuhan Liu
- Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Pei Zhao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China
| | - Chen Li
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - Yanan Wang
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - Fuyi Li
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - Tatsuya Akutsu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Chris Bain
- Monash Data Future Institutes, Monash University, Melbourne, Victoria 3800, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Junzhou Li
- Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China
| | - Zuoren Yang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China
| | - Xin Gao
- Computational Bioscience Research Center (CBRC), Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Lukasz Kurgan
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA, USA
| | - Jiangning Song
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.,Monash Data Future Institutes, Monash University, Melbourne, Victoria 3800, Australia
| |
Collapse
|
7
|
Burke A, Birmingham WR, Zhuo Y, Thorpe TW, Zucoloto da Costa B, Crawshaw R, Rowles I, Finnigan JD, Young C, Holgate GM, Muldowney MP, Charnock SJ, Lovelock SL, Turner NJ, Green AP. An Engineered Cytidine Deaminase for Biocatalytic Production of a Key Intermediate of the Covid-19 Antiviral Molnupiravir. J Am Chem Soc 2022; 144:3761-3765. [PMID: 35224970 PMCID: PMC8915250 DOI: 10.1021/jacs.1c11048] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Indexed: 01/23/2023]
Abstract
The Covid-19 pandemic highlights the urgent need for cost-effective processes to rapidly manufacture antiviral drugs at scale. Here we report a concise biocatalytic process for Molnupiravir, a nucleoside analogue recently approved as an orally available treatment for SARS-CoV-2. Key to the success of this process was the development of an efficient biocatalyst for the production of N-hydroxy-cytidine through evolutionary adaption of the hydrolytic enzyme cytidine deaminase. This engineered biocatalyst performs >85 000 turnovers in less than 3 h, operates at 180 g/L substrate loading, and benefits from in situ crystallization of the N-hydroxy-cytidine product (85% yield), which can be converted to Molnupiravir by a selective 5'-acylation using Novozym 435.
Collapse
Affiliation(s)
- Ashleigh
J. Burke
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - William R. Birmingham
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Ying Zhuo
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Thomas W. Thorpe
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Bruna Zucoloto da Costa
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Rebecca Crawshaw
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Ian Rowles
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - James D. Finnigan
- Prozomix
Ltd, Building 4, West
End Ind. Estate, Haltwhistle NE49 9HA, U.K.
| | - Carl Young
- Prozomix
Ltd, Building 4, West
End Ind. Estate, Haltwhistle NE49 9HA, U.K.
| | - Gregory M. Holgate
- Sterling
Pharma Solutions, Sterling Place, Dudley, Northumberland NE23 7QG, U.K.
| | - Mark P. Muldowney
- Sterling
Pharma Solutions, Sterling Place, Dudley, Northumberland NE23 7QG, U.K.
| | - Simon J. Charnock
- Prozomix
Ltd, Building 4, West
End Ind. Estate, Haltwhistle NE49 9HA, U.K.
| | - Sarah L. Lovelock
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Nicholas J. Turner
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| | - Anthony P. Green
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
| |
Collapse
|
8
|
Kroeger AA, Karton A. Perylene Bisimide Cyclophanes as Biaryl Enantiomerization Catalysts─Explorations into π–π Catalysis and Host–Guest Chirality Transfer. J Org Chem 2022; 87:5485-5496. [DOI: 10.1021/acs.joc.1c02719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Asja A. Kroeger
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Amir Karton
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| |
Collapse
|
9
|
Takenaka M, Takenaka S, Barthel T, Frink B, Haag S, Verbitskiy D, Oldenkott B, Schallenberg-Rüdinger M, Feiler CG, Weiss MS, Palm GJ, Weber G. DYW domain structures imply an unusual regulation principle in plant organellar RNA editing catalysis. Nat Catal 2021; 4:510-522. [PMID: 34712911 PMCID: PMC7611903 DOI: 10.1038/s41929-021-00633-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
RNA editosomes selectively deaminate cytidines to uridines in plant organellar transcripts–mostly to restore protein functionality and consequently facilitate mitochondrial and chloroplast function. The RNA editosomal pentatricopeptide repeat proteins serve target RNA recognition, whereas the intensively studied DYW domain elicits catalysis. Here we present structures and functional data of a DYW domain in an inactive ground state and activated. DYW domains harbour a cytidine deaminase fold and a C-terminal DYW motif, with catalytic and structural zinc atoms, respectively. A conserved gating domain within the deaminase fold regulates the active site sterically and mechanistically in a process that we termed gated zinc shutter. Based on the structures, an autoinhibited ground state and its activation are cross-validated by RNA editing assays and differential scanning fluorimetry. We anticipate that, in vivo, the framework of an active plant RNA editosome triggers the release of DYW autoinhibition to ensure a controlled and coordinated cytidine deamination playing a key role in mitochondrial and chloroplast homeostasis.
Collapse
Affiliation(s)
- Mizuki Takenaka
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Sachi Takenaka
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, Japan.,These authors contributed equally: Sachi Takenaka, Tatjana Barthel
| | - Tatjana Barthel
- University of Greifswald, Molecular Structural Biology, Greifswald, Germany.,Present address: Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany.,These authors contributed equally: Sachi Takenaka, Tatjana Barthel
| | - Brody Frink
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Sascha Haag
- Molekulare Botanik, Universität Ulm, Ulm, Germany
| | | | - Bastian Oldenkott
- Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, University of Bonn, Bonn, Germany
| | | | - Christian G Feiler
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany
| | - Manfred S Weiss
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany
| | - Gottfried J Palm
- University of Greifswald, Molecular Structural Biology, Greifswald, Germany
| | - Gert Weber
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany
| |
Collapse
|
10
|
Kroeger AA, Karton A. Perylene bisimide cyclophanes as receptors for planar transition structures – catalysis of stereoinversions by shape-complementarity and noncovalent π–π interactions. Org Chem Front 2021. [DOI: 10.1039/d1qo00755f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Perylene bisimide cyclophanes, ideal receptors for planar aromatic compounds, act as π–π catalysts by stabilizing shape-complementary stereoinversion transition structures.
Collapse
Affiliation(s)
- Asja A. Kroeger
- School of Molecular Sciences
- The University of Western Australia
- Crawley
- Australia
| | - Amir Karton
- School of Molecular Sciences
- The University of Western Australia
- Crawley
- Australia
| |
Collapse
|
11
|
Maiti A, Myint W, Delviks-Frankenberry KA, Hou S, Kanai T, Balachandran V, Sierra Rodriguez C, Tripathi R, Kurt Yilmaz N, Pathak VK, Schiffer CA, Matsuo H. Crystal Structure of a Soluble APOBEC3G Variant Suggests ssDNA to Bind in a Channel that Extends between the Two Domains. J Mol Biol 2020; 432:6042-6060. [PMID: 33098858 DOI: 10.1016/j.jmb.2020.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/09/2020] [Accepted: 10/16/2020] [Indexed: 11/16/2022]
Abstract
APOBEC3G (A3G) is a single-stranded DNA (ssDNA) cytosine deaminase that can restrict HIV-1 infection by mutating the viral genome. A3G consists of a non-catalytic N-terminal domain (NTD) and a catalytic C-terminal domain (CTD) connected by a short linker. While the CTD catalyzes cytosine deamination, the NTD is believed to provide additional affinity for ssDNA. Structures of both A3G domains have been solved individually; however, a full-length A3G structure has been challenging. Recently, crystal structures of full-length rhesus macaque A3G variants were solved which suggested dimerization mechanisms and RNA binding surfaces, whereas the dimerization appeared to compromise catalytic activity. We determined the crystal structure of a soluble variant of human A3G (sA3G) at 2.5 Å and from these data generated a model structure of wild-type A3G. This model demonstrated that the NTD was rotated 90° relative to the CTD along the major axis of the molecule, an orientation that forms a positively charged channel connected to the CTD catalytic site, consisting of NTD loop-1 and CTD loop-3. Structure-based mutations, in vitro deamination and DNA binding assays, and HIV-1 restriction assays identify R24, located in the NTD loop-1, as essential to a critical interaction with ssDNA. Furthermore, sA3G was shown to bind a deoxy-cytidine dinucleotide near the catalytic Zn2+, yet not in the catalytic position, where the interactions between deoxy-cytidines and CTD loop-1 and loop-7 residues were different from those formed with substrate. These new interactions suggest a mechanism explaining why A3G exhibits a 3' to 5' directional preference in processive deamination.
Collapse
Affiliation(s)
- Atanu Maiti
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Wazo Myint
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Krista A Delviks-Frankenberry
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Shurong Hou
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Tapan Kanai
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; Department of Chemistry, Banasthali University, Banasthali 304022, Rajasthan, India
| | | | | | - Rashmi Tripathi
- Department of Bioscience and Biotechnology, Banasthali University, Banasthali 304022, Rajasthan, India
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Vinay K Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Hiroshi Matsuo
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
| |
Collapse
|
12
|
Wang J, Guo Q, Liu L, Wang X. Crystal structure of Arabidopsis thaliana cytidine deaminase. Biochem Biophys Res Commun 2020; 529:659-665. [PMID: 32736689 DOI: 10.1016/j.bbrc.2020.06.084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 11/19/2022]
Abstract
Cytidine deaminase (CDA) catalyzes the (deoxy)cytidine deamination to (deoxy)uridine, which involves in the catabolic and salvage pathways of pyrimidine nucleotides in plants. CDA serves as a prototype of the cytidine deaminase superfamily that contains a number of RNA editing enzymes. Arabidopsis thaliana has only one functional CDA, AtCDA1. We solved the crystal structures of AtCDA1, which is a dimeric zinc-containing enzyme and each protomer consists of an N-terminal zinc-binding catalytic domain and a C-terminal non-catalytic domain. Both domains adopt a typical α/β/α sandwich fold. In vitro biochemical assays showed that the ribose moiety of cytidine is required for ligand binding, and structural analyses revealed a conserved catalytic mechanism is adopted by AtCDA1.
Collapse
Affiliation(s)
- Jia Wang
- CAS Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Haidian, Beijing, 100093, China; Graduate School, University of Chinese Academy of Sciences, Shijingshan, Beijing, 100049, China
| | - Qi Guo
- CAS Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Haidian, Beijing, 100093, China; Graduate School, University of Chinese Academy of Sciences, Shijingshan, Beijing, 100049, China
| | - Lin Liu
- School of Life Sciences, Anhui University, Hefei, Anhui, 230601, China
| | - Xiao Wang
- School of Life Sciences, Anhui University, Hefei, Anhui, 230601, China.
| |
Collapse
|
13
|
Carlaw TM, Zhang LH, Ross CJD. CRISPR/Cas9 Editing: Sparking Discussion on Safety in Light of the Need for New Therapeutics. Hum Gene Ther 2020; 31:794-807. [PMID: 32586150 DOI: 10.1089/hum.2020.111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Recent advances in genome sequencing have greatly improved our ability to understand and identify the causes of genetic diseases. However, there remains an urgent need for innovative, safe, and effective treatments for these diseases. CRISPR-based genome editing systems have become important and powerful tools in the laboratory, and efforts are underway to translate these into patient therapies. Therapeutic base editing is one form of genome engineering that has gained much interest because of its simplicity, specificity, and effectiveness. Base editors are a fusion of a partially deactivated Cas9 enzyme with nickase function, together with a base-modifying enzyme. They are capable of precisely targeting and repairing a pathogenic mutation to restore the normal function of a gene, ideally without disturbing the rest of the genome. In the past year, research has identified new safety concerns of base editors and sparked new innovations to improve their safety. In this review, we provide an overview of the recent advances in the safety and effectiveness of therapeutic base editors and prime editing.
Collapse
Affiliation(s)
| | - Lin-Hua Zhang
- Faculty of Pharmaceutical Sciences; University of British Columbia, Vancouver, Canada
| | - Colin J D Ross
- Faculty of Pharmaceutical Sciences; University of British Columbia, Vancouver, Canada
| |
Collapse
|
14
|
Solomon WC, Myint W, Hou S, Kanai T, Tripathi R, Kurt Yilmaz N, Schiffer CA, Matsuo H. Mechanism for APOBEC3G catalytic exclusion of RNA and non-substrate DNA. Nucleic Acids Res 2019; 47:7676-7689. [PMID: 31424549 PMCID: PMC6698744 DOI: 10.1093/nar/gkz550] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/06/2019] [Accepted: 06/11/2019] [Indexed: 12/17/2022] Open
Abstract
The potent antiretroviral protein APOBEC3G (A3G) specifically targets and deaminates deoxycytidine nucleotides, generating deoxyuridine, in single stranded DNA (ssDNA) intermediates produced during HIV replication. A non-catalytic domain in A3G binds strongly to RNA, an interaction crucial for recruitment of A3G to the virion; yet, A3G displays no deamination activity for cytidines in viral RNA. Here, we report NMR and molecular dynamics (MD) simulation analysis for interactions between A3Gctd and multiple substrate or non-substrate DNA and RNA, in combination with deamination assays. NMR ssDNA-binding experiments revealed that the interaction with residues in helix1 and loop1 (T201-L220) distinguishes the binding mode of substrate ssDNA from non-substrate. Using 2′-deoxy-2′-fluorine substituted cytidines, we show that a 2′-endo sugar conformation of the target deoxycytidine is favored for substrate binding and deamination. Trajectories of the MD simulation indicate that a ribose 2′-hydroxyl group destabilizes the π-π stacking of the target cytosine and H257, resulting in dislocation of the target cytosine base from the catalytic position. Interestingly, APOBEC3A, which can deaminate ribocytidines, retains the ribocytidine in the catalytic position throughout the MD simulation. Our results indicate that A3Gctd catalytic selectivity against RNA is dictated by both the sugar conformation and 2′-hydroxyl group.
Collapse
Affiliation(s)
- William C Solomon
- Department of Biochemistry, Molecular Biology and Biophysics, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wazo Myint
- Basic Research Laboratory, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Shurong Hou
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Tapan Kanai
- Basic Research Laboratory, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.,Department of Chemistry, Banasthali University, Banasthali-304022, Rajasthan, India
| | - Rashmi Tripathi
- Department of Bioscience and Biotechnology, Banasthali University, Banasthali-304022, Rajasthan, India
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Hiroshi Matsuo
- Basic Research Laboratory, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| |
Collapse
|
15
|
Abstract
Base editing is a genome editing strategy that induces specific single-nucleotide changes within genomic DNA. Two major DNA base editors, cytosine base editors and adenine base editors, that consist of a Cas9 protein linked to a deaminase enzyme that catalyzes targeted base conversion directed by a single-guide RNA have been developed. This strategy has been used widely for precise genome editing because, unlike CRISPR-Cas nuclease-based genome editing systems, this strategy does not create double-strand DNA breaks that often result in high levels of undesirable indels. However, recent papers have reported that DNA base editors can cause substantial off-target editing in both genomic DNA and RNA. The off-target editing described in these studies is primarily independent of guide RNA and arises from the promiscuous reactivity of the deaminase enzymes used in DNA base editors. In this Perspective, we discuss the development of DNA base editors, the guide RNA-independent off-target activity reported in recent studies, and strategies that improve the selectivity of DNA base editors.
Collapse
Affiliation(s)
- SeHee Park
- Department of Chemistry, University of California, One Shields Ave, Davis, CA 95616, USA
| | - Peter A. Beal
- Department of Chemistry, University of California, One Shields Ave, Davis, CA 95616, USA
| |
Collapse
|
16
|
Zhou C, Sun Y, Yan R, Liu Y, Zuo E, Gu C, Han L, Wei Y, Hu X, Zeng R, Li Y, Zhou H, Guo F, Yang H. Off-target RNA mutation induced by DNA base editing and its elimination by mutagenesis. Nature 2019; 571:275-278. [PMID: 31181567 DOI: 10.1038/s41586-019-1314-0] [Citation(s) in RCA: 284] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 05/30/2019] [Indexed: 12/21/2022]
Abstract
Recently developed DNA base editing methods enable the direct generation of desired point mutations in genomic DNA without generating any double-strand breaks1-3, but the issue of off-target edits has limited the application of these methods. Although several previous studies have evaluated off-target mutations in genomic DNA4-8, it is now clear that the deaminases that are integral to commonly used DNA base editors often bind to RNA9-13. For example, the cytosine deaminase APOBEC1-which is used in cytosine base editors (CBEs)-targets both DNA and RNA12, and the adenine deaminase TadA-which is used in adenine base editors (ABEs)-induces site-specific inosine formation on RNA9,11. However, any potential RNA mutations caused by DNA base editors have not been evaluated. Adeno-associated viruses are the most common delivery system for gene therapies that involve DNA editing; these viruses can sustain long-term gene expression in vivo, so the extent of potential RNA mutations induced by DNA base editors is of great concern14-16. Here we quantitatively evaluated RNA single nucleotide variations (SNVs) that were induced by CBEs or ABEs. Both the cytosine base editor BE3 and the adenine base editor ABE7.10 generated tens of thousands of off-target RNA SNVs. Subsequently, by engineering deaminases, we found that three CBE variants and one ABE variant showed a reduction in off-target RNA SNVs to the baseline while maintaining efficient DNA on-target activity. This study reveals a previously overlooked aspect of off-target effects in DNA editing and also demonstrates that such effects can be eliminated by engineering deaminases.
Collapse
Affiliation(s)
- Changyang Zhou
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yidi Sun
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,Bio-Med Big Data Center, Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Rui Yan
- Center for Translational Medicine, Ministry of Education Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Obstetrics and Gynecology, West China Second University Hospital, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yajing Liu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Life Science and Technology, Shanghai Tech University, Shanghai, China
| | - Erwei Zuo
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,Center for Animal Genomics, Agricultural Genome Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Chan Gu
- Center for Translational Medicine, Ministry of Education Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Obstetrics and Gynecology, West China Second University Hospital, College of Life Sciences, Sichuan University, Chengdu, China
| | - Linxiao Han
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yu Wei
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xinde Hu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Rong Zeng
- CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,School of Life Science and Technology, Shanghai Tech University, Shanghai, China
| | - Yixue Li
- Center for Translational Medicine, Ministry of Education Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Obstetrics and Gynecology, West China Second University Hospital, College of Life Sciences, Sichuan University, Chengdu, China. .,School of Life Science and Technology, Shanghai Tech University, Shanghai, China. .,Shanghai Jiao Tong University, Fudan University, Shanghai Academy of Science & Technology, Shanghai, China.
| | - Haibo Zhou
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
| | - Fan Guo
- Center for Translational Medicine, Ministry of Education Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Obstetrics and Gynecology, West China Second University Hospital, College of Life Sciences, Sichuan University, Chengdu, China.
| | - Hui Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
| |
Collapse
|
17
|
Affiliation(s)
- Valerie Vaissier Welborn
- Kenneth S. Pitzer Center for Theoretical Chemistry and Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Teresa Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry and Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemical and Biomolecular Engineering and Department of Bioengineering, University of California, Berkeley, California 94720, United States
| |
Collapse
|
18
|
Maiti A, Myint W, Kanai T, Delviks-Frankenberry K, Sierra Rodriguez C, Pathak VK, Schiffer CA, Matsuo H. Crystal structure of the catalytic domain of HIV-1 restriction factor APOBEC3G in complex with ssDNA. Nat Commun 2018; 9:2460. [PMID: 29941968 PMCID: PMC6018426 DOI: 10.1038/s41467-018-04872-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/29/2018] [Indexed: 12/03/2022] Open
Abstract
The human APOBEC3G protein is a cytidine deaminase that generates cytidine to deoxy-uridine mutations in single-stranded DNA (ssDNA), and capable of restricting replication of HIV-1 by generating mutations in viral genome. The mechanism by which APOBEC3G specifically deaminates 5′-CC motifs has remained elusive since structural studies have been hampered due to apparently weak ssDNA binding of the catalytic domain of APOBEC3G. We overcame the problem by generating a highly active variant with higher ssDNA affinity. Here, we present the crystal structure of this variant complexed with a ssDNA substrate at 1.86 Å resolution. This structure reveals atomic-level interactions by which APOBEC3G recognizes a functionally-relevant 5′-TCCCA sequence. This complex also reveals a key role of W211 in substrate recognition, implicating a similar recognition in activation-induced cytidine deaminase (AID) with a conserved tryptophan. APOBEC3G (A3G) is a single-stranded DNA (ssDNA) cytidine deaminase that restricts HIV-1. Here the authors provide molecular insights into A3G substrate recognition by determining the 1.86 Å resolution crystal structure of its catalytic domain bound to ssDNA.
Collapse
Affiliation(s)
- Atanu Maiti
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Wazo Myint
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Tapan Kanai
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Krista Delviks-Frankenberry
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
| | - Christina Sierra Rodriguez
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Vinay K Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Hiroshi Matsuo
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA.
| |
Collapse
|
19
|
Phillips RS, Vita A, Spivey JB, Rudloff AP, Driscoll MD, Hay S. Ground-State Destabilization by Phe-448 and Phe-449 Contributes to Tyrosine Phenol-Lyase Catalysis. ACS Catal 2016. [DOI: 10.1021/acscatal.6b01495] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Robert S. Phillips
- Department
of Chemistry, University of Georgia, Athens, Georgia 30602, United States
- Department
of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Andrew Vita
- Department
of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - J. Blaine Spivey
- Department
of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Alexander P. Rudloff
- Department
of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Max D. Driscoll
- Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| | - Sam Hay
- Manchester Institute of Biotechnology, Manchester M1 7DN, United Kingdom
| |
Collapse
|
20
|
Shaban NM, Shi K, Li M, Aihara H, Harris RS. 1.92 Angstrom Zinc-Free APOBEC3F Catalytic Domain Crystal Structure. J Mol Biol 2016; 428:2307-2316. [PMID: 27139641 PMCID: PMC5142242 DOI: 10.1016/j.jmb.2016.04.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/13/2016] [Accepted: 04/19/2016] [Indexed: 01/07/2023]
Abstract
The APOBEC3 family of DNA cytosine deaminases is capable of restricting the replication of HIV-1 and other pathogens. Here, we report a 1.92 Å resolution crystal structure of the Vif-binding and catalytic domain of APOBEC3F (A3F). This structure is distinct from the previously published APOBEC and phylogenetically related deaminase structures, as it is the first without zinc in the active site. We determined an additional structure containing zinc in the same crystal form that allows direct comparison with the zinc-free structure. In the absence of zinc, the conserved active site residues that normally participate in zinc coordination show unique conformations, including a 90 degree rotation of His249 and disulfide bond formation between Cys280 and Cys283. We found that zinc coordination is influenced by pH, and treating the protein at low pH in crystallization buffer is sufficient to remove zinc. Zinc coordination and catalytic activity are reconstituted with the addition of zinc only in a reduced environment likely due to the two active site cysteines readily forming a disulfide bond when not coordinating zinc. We show that the enzyme is active in the presence of zinc and cobalt but not with other divalent metals. These results unexpectedly demonstrate that zinc is not required for the structural integrity of A3F and suggest that metal coordination may be a strategy for regulating the activity of A3F and related deaminases.
Collapse
Affiliation(s)
- Nadine M. Shaban
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455,Correspondence: ;
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455
| | - Ming Li
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455
| | - Reuben S. Harris
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN 55455,Correspondence: ;
| |
Collapse
|
21
|
Zhang X, Zhao Y, Yan H, Cao Z, Mo Y. Combined QM(DFT)/MM molecular dynamics simulations of the deamination of cytosine by yeast cytosine deaminase (yCD). J Comput Chem 2016; 37:1163-74. [DOI: 10.1002/jcc.24306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/04/2016] [Accepted: 01/05/2016] [Indexed: 12/16/2022]
Affiliation(s)
- Xin Zhang
- State Key Laboratory of Chemical Resource Engineering, Institute of Materia Medica, College of Science, Beijing University of Chemical Technology; Beijing 100029 China
- Department of Chemistry; Western Michigan University; Kalamazoo Michigan 49008
| | - Yuan Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering, Xiamen University; Xiamen 360015 China
- The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University; Kaifeng 475004 China
| | - Honggao Yan
- Department of Biochemistry; The Center for Biological Modeling, Michigan State University; East Lansing Michigan 48824
- Department of Chemistry; The Center for Biological Modeling, Michigan State University; East Lansing Michigan 48824
| | - Zexing Cao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering, Xiamen University; Xiamen 360015 China
| | - Yirong Mo
- Department of Chemistry; Western Michigan University; Kalamazoo Michigan 49008
| |
Collapse
|
22
|
Abstract
Entropic effects have often been invoked to explain the extraordinary catalytic power of enzymes. In particular, the hypothesis that enzymes can use part of the substrate-binding free energy to reduce the entropic penalty associated with the subsequent chemical transformation has been very influential. The enzymatic reaction of cytidine deaminase appears to be a distinct example. Here, substrate binding is associated with a significant entropy loss that closely matches the activation entropy penalty for the uncatalyzed reaction in water, whereas the activation entropy for the rate-limiting catalytic step in the enzyme is close to zero. Herein, we report extensive computer simulations of the cytidine deaminase reaction and its temperature dependence. The energetics of the catalytic reaction is first evaluated by density functional theory calculations. These results are then used to parametrize an empirical valence bond description of the reaction, which allows efficient sampling by molecular dynamics simulations and computation of Arrhenius plots. The thermodynamic activation parameters calculated by this approach are in excellent agreement with experimental data and indeed show an activation entropy close to zero for the rate-limiting transition state. However, the origin of this effect is a change of reaction mechanism compared the uncatalyzed reaction. The enzyme operates by hydroxide ion attack, which is intrinsically associated with a favorable activation entropy. Hence, this has little to do with utilization of binding free energy to pay the entropic penalty but rather reflects how a preorganized active site can stabilize a reaction path that is not operational in solution.
Collapse
|
23
|
Walsh PS, Dean JC, McBurney C, Kang H, Gellman SH, Zwier TS. Conformation-specific spectroscopy of capped glutamine-containing peptides: role of a single glutamine residue on peptide backbone preferences. Phys Chem Chem Phys 2016; 18:11306-22. [PMID: 27054830 DOI: 10.1039/c6cp01062h] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The conformational preferences of a series of short, aromatic-capped, glutamine-containing peptides have been studied under jet-cooled conditions in the gas phase.
Collapse
Affiliation(s)
| | - Jacob C. Dean
- Department of Chemistry
- Purdue University
- West Lafayette
- USA
| | - Carl McBurney
- Department of Chemistry
- University of Wisconsin-Madison
- Madison
- USA
| | - Hyuk Kang
- Department of Chemistry
- Ajou University
- Republic of Korea
| | | | | |
Collapse
|
24
|
Abstract
We review literature on the metabolism of ribo- and deoxyribonucleotides, nucleosides, and nucleobases in Escherichia coli and Salmonella,including biosynthesis, degradation, interconversion, and transport. Emphasis is placed on enzymology and regulation of the pathways, at both the level of gene expression and the control of enzyme activity. The paper begins with an overview of the reactions that form and break the N-glycosyl bond, which binds the nucleobase to the ribosyl moiety in nucleotides and nucleosides, and the enzymes involved in the interconversion of the different phosphorylated states of the nucleotides. Next, the de novo pathways for purine and pyrimidine nucleotide biosynthesis are discussed in detail.Finally, the conversion of nucleosides and nucleobases to nucleotides, i.e.,the salvage reactions, are described. The formation of deoxyribonucleotides is discussed, with emphasis on ribonucleotidereductase and pathways involved in fomation of dUMP. At the end, we discuss transport systems for nucleosides and nucleobases and also pathways for breakdown of the nucleobases.
Collapse
|
25
|
Quantifying bond distortions in transient enzyme species by a combination of density functional theory calculations and time-resolved infrared difference spectroscopy. Implications for the mechanism of dephosphorylation of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA1a). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1036-43. [PMID: 25986318 DOI: 10.1016/j.bbabio.2015.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/22/2015] [Accepted: 05/09/2015] [Indexed: 12/26/2022]
Abstract
The sarcoplasmic Ca(2+)-ATPase (SERCA1a) forms two phosphoenzyme intermediates during Ca(2+) pumping. The second intermediate E2P hydrolyzes rapidly, which is essential for the rapid removal of Ca(2+) from the cytosol of muscle cells. The present work studies whether a weakening of the scissile PO bond in the E2P ground state facilitates dephosphorylation. To this end, the experimentally known vibrational spectrum of the E2P phosphate group was calculated with density functional theory (DFT) using structural models at two levels of structural complexity: (i) Models of acetyl phosphate in simple environments and (ii) ~150 atom models of the catalytic site. It was found that the enzyme environment distorts the structure of the phosphate group: one of the terminal PO bonds is shorter in the catalytic site indicating weaker interactions than in water. However, the bond that bridges phosphate and Asp351 is unaffected. This indicates that the scissile PO bond is not weakened by the enzyme environment of E2P. A second finding was that the catalytic site of the E2P state in aqueous solution appears to adopt a structure as in the crystals with BeF3(-), where the ATPase is in a non-reactive conformation. The reactant state of the dephosphorylation reaction differs from the E2P ground state: Glu183 faces Asp351 and positions the attacking water molecule. This state has a 0.04Å longer, and thus weaker, bridging PO bond. The reactant state is not detected in our experiments, indicating that its energy is at least 1kcal/mol higher than that of the E2P ground state.
Collapse
|
26
|
Bacillus halodurans Strain C125 Encodes and Synthesizes Enzymes from Both Known Pathways To Form dUMP Directly from Cytosine Deoxyribonucleotides. Appl Environ Microbiol 2015; 81:3395-404. [PMID: 25746996 DOI: 10.1128/aem.00268-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/03/2015] [Indexed: 11/20/2022] Open
Abstract
Analysis of the genome of Bacillus halodurans strain C125 indicated that two pathways leading from a cytosine deoxyribonucleotide to dUMP, used for dTMP synthesis, were encoded by the genome of the bacterium. The genes that were responsible, the comEB gene and the dcdB gene, encoding dCMP deaminase and the bifunctional dCTP deaminase:dUTPase (DCD:DUT), respectively, were both shown to be expressed in B. halodurans, and both genes were subject to repression by the nucleosides thymidine and deoxycytidine. The latter nucleoside presumably exerts its repression after deamination by cytidine deaminase. Both comEB and dcdB were cloned, overexpressed in Escherichia coli, and purified to homogeneity. Both enzymes were active and displayed the expected regulatory properties: activation by dCTP for dCMP deaminase and dTTP inhibition for both enzymes. Structurally, the B. halodurans enzyme resembled the Mycobacterium tuberculosis enzyme the most. An investigation of sequenced genomes from other species of the genus Bacillus revealed that not only the genome of B. halodurans but also the genomes of Bacillus pseudofirmus, Bacillus thuringiensis, Bacillus hemicellulosilyticus, Bacillus marmarensis, Bacillus cereus, and Bacillus megaterium encode both the dCMP deaminase and the DCD:DUT enzymes. In addition, eight dcdB homologs from Bacillus species within the genus for which the whole genome has not yet been sequenced were registered in the NCBI Entrez database.
Collapse
|
27
|
Phillips RS. Chemistry and diversity of pyridoxal-5'-phosphate dependent enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1167-74. [PMID: 25615531 DOI: 10.1016/j.bbapap.2014.12.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/22/2014] [Accepted: 12/23/2014] [Indexed: 12/01/2022]
Abstract
Pyridoxal-5'-phosphate (PLP) is a versatile cofactor that enzymes use to catalyze a wide variety of reactions of amino acids, including transamination, decarboxylation, racemization, β- and γ-eliminations and substitutions, retro-aldol and Claisen reactions. These reactions depend on the ability of PLP to stabilize, to a varying degree, α-carbanionic intermediates. Furthermore, oxidative decarboxylations and rearrangements suggest that PLP can stabilize radical intermediates as well. The reaction mechanisms of two PLP-dependent enzymes are discussed, kynureninase and tyrosine phenol-lyase (TPL). Kynureninase catalyzes a retro-Claisen reaction of kynurenine to give anthranilate and alanine. The key step, hydration of the γ-carbonyl, is assisted by acid-base catalysis with the phosphate of the PLP, mediated by a conserved tyrosine, and an oxyanion hole. TPL catalyzes the reversible elimination of phenol, a poor leaving group, from l-tyrosine. In TPL, the Cβ-Cγ bond cleavage is accelerated by ground state strain from the bending of the substrate ring out of the plane with the Cβ-Cγ bond. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
Collapse
Affiliation(s)
- Robert S Phillips
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| |
Collapse
|
28
|
Andrews LD, Fenn TD, Herschlag D. Ground state destabilization by anionic nucleophiles contributes to the activity of phosphoryl transfer enzymes. PLoS Biol 2013; 11:e1001599. [PMID: 23843744 PMCID: PMC3699461 DOI: 10.1371/journal.pbio.1001599] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 05/23/2013] [Indexed: 11/25/2022] Open
Abstract
Enhanced phosphate binding by phosphatases upon removal of their anionic nucleophiles suggests that these enzymes use ground state destabilization by anionic active site nucleophiles as part of their catalytic arsenal. Enzymes stabilize transition states of reactions while limiting binding to ground states, as is generally required for any catalyst. Alkaline Phosphatase (AP) and other nonspecific phosphatases are some of Nature's most impressive catalysts, achieving preferential transition state over ground state stabilization of more than 1022-fold while utilizing interactions with only the five atoms attached to the transferred phosphorus. We tested a model that AP achieves a portion of this preference by destabilizing ground state binding via charge repulsion between the anionic active site nucleophile, Ser102, and the negatively charged phosphate monoester substrate. Removal of the Ser102 alkoxide by mutation to glycine or alanine increases the observed Pi affinity by orders of magnitude at pH 8.0. To allow precise and quantitative comparisons, the ionic form of bound Pi was determined from pH dependencies of the binding of Pi and tungstate, a Pi analog lacking titratable protons over the pH range of 5–11, and from the 31P chemical shift of bound Pi. The results show that the Pi trianion binds with an exceptionally strong femtomolar affinity in the absence of Ser102, show that its binding is destabilized by ≥108-fold by the Ser102 alkoxide, and provide direct evidence for ground state destabilization. Comparisons of X-ray crystal structures of AP with and without Ser102 reveal the same active site and Pi binding geometry upon removal of Ser102, suggesting that the destabilization does not result from a major structural rearrangement upon mutation of Ser102. Analogous Pi binding measurements with a protein tyrosine phosphatase suggest the generality of this ground state destabilization mechanism. Our results have uncovered an important contribution of anionic nucleophiles to phosphoryl transfer catalysis via ground state electrostatic destabilization and an enormous capacity of the AP active site for specific and strong recognition of the phosphoryl group in the transition state. Enzymes use a variety of tools and strategies to enhance (catalyze) biological reactions; these include the use of general acids and bases, cofactors, and the employment of remote binding interactions to position substrates near reactive chemical groups. Phosphatases are some of Nature's best enzymes, affording exceptional rate enhancements to the biologically ubiquitous removal of a phosphate group from a substrate (dephosphorylation). The apparent challenge faced by nonspecific phosphatases is that their wide substrate specificity precludes the efficient use of remote binding interactions. Previous work suggested that phosphatases could use negatively charged chemical groups (anionic nucleophiles) at the active site to destabilize substrate binding without simultaneously destabilizing the transition state barrier—an elusive catalytic strategy known as preferential ground state destabilization. In this work, we test this ground state destabilization model of catalysis by removing the anionic active site nucleophile of alkaline phosphatase and observing the effects on the enzyme's affinity for a phosphate ligand. We find that alkaline phosphatase has an exceptionally strong affinity for phosphate, and provide clear evidence for ground state destabilization by the anionic active site nucleophile that, when present, forestalls substrate saturation and product inhibition, and enhances catalysis by at least a thousand fold.
Collapse
Affiliation(s)
- Logan D Andrews
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
| | | | | |
Collapse
|
29
|
Dawson A, Trumper P, Chrysostomou G, Hunter WN. Structure of diaminohydroxyphosphoribosylaminopyrimidine deaminase/5-amino-6-(5-phosphoribosylamino)uracil reductase from Acinetobacter baumannii. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:611-7. [PMID: 23722836 PMCID: PMC3668577 DOI: 10.1107/s174430911301292x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/11/2013] [Indexed: 11/11/2022]
Abstract
The bifunctional diaminohydroxyphosphoribosylaminopyrimidine deaminase/5-amino-6-(5-phosphoribosylamino)uracil reductase (RibD) represents a potential antibacterial drug target. The structure of recombinant Acinetobacter baumannii RibD is reported in orthorhombic and tetragonal crystal forms at 2.2 and 2.0 Å resolution, respectively. Comparisons with orthologous structures in the Protein Data Bank indicated close similarities. The tetragonal crystal form was obtained in the presence of guanosine monophosphate, which surprisingly was observed to occupy the adenine-binding site of the reductase domain.
Collapse
Affiliation(s)
- Alice Dawson
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Paul Trumper
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Georgios Chrysostomou
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - William N. Hunter
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| |
Collapse
|
30
|
Ruben EA, Schwans JP, Sonnett M, Natarajan A, Gonzalez A, Tsai Y, Herschlag D. Ground state destabilization from a positioned general base in the ketosteroid isomerase active site. Biochemistry 2013; 52:1074-81. [PMID: 23311398 DOI: 10.1021/bi301348x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We compared the binding affinities of ground state analogues for bacterial ketosteroid isomerase (KSI) with a wild-type anionic Asp general base and with uncharged Asn and Ala in the general base position to provide a measure of potential ground state destabilization that could arise from the close juxtaposition of the anionic Asp and hydrophobic steroid in the reaction's Michaelis complex. The analogue binding affinity increased ~1 order of magnitude for the Asp38Asn mutation and ~2 orders of magnitude for the Asp38Ala mutation, relative to the affinity with Asp38, for KSI from two sources. The increased level of binding suggests that the abutment of a charged general base and a hydrophobic steroid is modestly destabilizing, relative to a standard state in water, and that this destabilization is relieved in the transition state and intermediate in which the charge on the general base has been neutralized because of proton abstraction. Stronger binding also arose from mutation of Pro39, the residue adjacent to the Asp general base, consistent with an ability of the Asp general base to now reorient to avoid the destabilizing interaction. Consistent with this model, the Pro mutants reduced or eliminated the increased level of binding upon replacement of Asp38 with Asn or Ala. These results, supported by additional structural observations, suggest that ground state destabilization from the negatively charged Asp38 general base provides a modest contribution to KSI catalysis. They also provide a clear illustration of the well-recognized concept that enzymes evolve for catalytic function and not, in general, to maximize ground state binding. This ground state destabilization mechanism may be common to the many enzymes with anionic side chains that deprotonate carbon acids.
Collapse
Affiliation(s)
- Eliza A Ruben
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Chen SC, Shen CY, Yen TM, Yu HC, Chang TH, Lai WL, Liaw SH. Evolution of vitamin B2biosynthesis: eubacterial RibG and fungal Rib2 deaminases. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:227-36. [DOI: 10.1107/s0907444912044903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/30/2012] [Indexed: 12/27/2022]
|
32
|
Refsland EW, Harris RS. The APOBEC3 family of retroelement restriction factors. Curr Top Microbiol Immunol 2013; 371:1-27. [PMID: 23686230 DOI: 10.1007/978-3-642-37765-5_1] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The ability to regulate and even target mutagenesis is an extremely valuable cellular asset. Enzyme-catalyzed DNA cytosine deamination is a molecular strategy employed by vertebrates to promote antibody diversity and defend against foreign nucleic acids. Ten years ago, a family of cellular enzymes was first described with several proving capable of deaminating DNA and inhibiting HIV-1 replication. Ensuing studies on the apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3) restriction factors have uncovered a broad-spectrum innate defense network that suppresses the replication of numerous endogenous and exogenous DNA-based parasites. Although many viruses possess equally elaborate counter-defense mechanisms, the APOBEC3 enzymes offer a tantalizing possibility of leveraging innate immunity to fend off viral infection. Here, we focus on mechanisms of retroelement restriction by the APOBEC3 family of restriction enzymes, and we consider the therapeutic benefits, as well as the possible pathological consequences, of arming cells with active DNA deaminases.
Collapse
Affiliation(s)
- Eric W Refsland
- Department of Biochemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | | |
Collapse
|
33
|
Schroeder GK, Zhou L, Snider MJ, Chen X, Wolfenden R. Flight of a Cytidine Deaminase Complex with an Imperfect Transition State Analogue Inhibitor: Mass Spectrometric Evidence for the Presence of a Trapped Water Molecule. Biochemistry 2012; 51:6476-86. [DOI: 10.1021/bi300516u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gottfried K. Schroeder
- Department of Biochemistry and
Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Li Zhou
- Department of Biochemistry and
Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Mark J. Snider
- Department of Chemistry, College of Wooster, Wooster, Ohio 44691, United States
| | - Xian Chen
- Department of Biochemistry and
Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Richard Wolfenden
- Department of Biochemistry and
Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
34
|
The biochemistry of activation-induced deaminase and its physiological functions. Semin Immunol 2012; 24:255-63. [DOI: 10.1016/j.smim.2012.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 05/18/2012] [Indexed: 01/26/2023]
|
35
|
ALPER KUTAYO, BAGDASSARIAN CAREYK. COUPLED GENETIC ALGORITHM/KOHONEN NEURAL NETWORK (GANN) FOR PROJECTION OF THREE-DIMENSIONAL PROTEIN STRUCTURES ONTO THE PLANE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633602000051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An algorithm is presented for projecting — at the amino acid level — the three-dimensional crystal structure of a protein molecule onto a planar surface. The scheme is topologically consistent: if two amino acid residues are closely juxtaposed in three-dimensional space, they remain so upon projection. Through such projections, a single resulting picture captures the spatial relations amongst a protein molecule's amino acids. Operationally, a genetic algorithm is used to "evolve" a parameter set which serves as input for a self-organizing Kohonen neural network responsible for the projection itself. A fitness function characterizing the quality of the projections is defined and maximized via the genetic algorithm. The workings of both the genetic algorithm and neural network are discussed in detail. In this work, we seek to optimize projections resulting from the inherently "frustrated" task of collapsing a space-filling collection of amino acid residues onto a simpler surface. Ultimately, the chosen application is a testing ground for establishing the success of our coupled genetic algorithm/Kohonen neural network scheme which can easily be adapted for other uses.
Collapse
Affiliation(s)
- KUTAY O. ALPER
- Department of Chemistry, The College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795, USA
| | - CAREY K. BAGDASSARIAN
- Department of Chemistry, The College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795, USA
| |
Collapse
|
36
|
Li X, Hayik SA, Merz KM. QM/MM X-ray refinement of zinc metalloenzymes. J Inorg Biochem 2010; 104:512-22. [PMID: 20116858 DOI: 10.1016/j.jinorgbio.2009.12.022] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 12/28/2009] [Accepted: 12/30/2009] [Indexed: 11/16/2022]
Abstract
Zinc metalloenzymes play an important role in biology. However, due to the limitation of molecular force field energy restraints used in X-ray refinement at medium or low resolutions, the precise geometry of the zinc coordination environment can be difficult to distinguish from ambiguous electron density maps. Due to the difficulties involved in defining accurate force fields for metal ions, the QM/MM (quantum-mechanical/molecular-mechanical) method provides an attractive and more general alternative for the study and refinement of metalloprotein active sites. Herein we present three examples that indicate that QM/MM based refinement yields a superior description of the crystal structure based on R and R(free) values and on the inspection of the zinc coordination environment. It is concluded that QM/MM refinement is an useful general tool for the improvement of the metal coordination sphere in metalloenzyme active sites.
Collapse
Affiliation(s)
- Xue Li
- Department of Chemistry and the Quantum Theory Project, 2328 New Physics Building, PO Box 118435, University of Florida, Gainesville, FL 32611-8435, USA
| | | | | |
Collapse
|
37
|
Furukawa A, Nagata T, Matsugami A, Habu Y, Sugiyama R, Hayashi F, Kobayashi N, Yokoyama S, Takaku H, Katahira M. Structure, interaction and real-time monitoring of the enzymatic reaction of wild-type APOBEC3G. EMBO J 2009; 28:440-51. [PMID: 19153609 DOI: 10.1038/emboj.2008.290] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2008] [Indexed: 12/29/2022] Open
Abstract
Human APOBEC3G exhibits anti-human immunodeficiency virus-1 (HIV-1) activity by deaminating cytidines of the minus strand of HIV-1. Here, we report a solution structure of the C-terminal deaminase domain of wild-type APOBEC3G. The interaction with DNA was examined. Many differences in the interaction were found between the wild type and recently studied mutant APOBEC3Gs. The position of the substrate cytidine, together with that of a DNA chain, in the complex, was deduced. Interestingly, the deamination reaction of APOBEC3G was successfully monitored using NMR signals in real time. Real-time monitoring has revealed that the third cytidine of the d(CCCA) segment is deaminated at an early stage and that then the second one is deaminated at a late stage, the first one not being deaminated at all. This indicates that the deamination is carried out in a strict 3' --> 5' order. Virus infectivity factor (Vif) of HIV-1 counteracts the anti-HIV-1 activity of APOBEC3G. The structure of the N-terminal domain of APOBEC3G, with which Vif interacts, was constructed with homology modelling. The structure implies the mechanism of species-specific sensitivity of APOBEC3G to Vif action.
Collapse
Affiliation(s)
- Ayako Furukawa
- Supramolecular Biology, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Chen SC, Lin YH, Yu HC, Liaw SH. Complex Structure of Bacillus subtilis RibG. J Biol Chem 2009; 284:1725-31. [DOI: 10.1074/jbc.m805820200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
39
|
Structure of the DNA deaminase domain of the HIV-1 restriction factor APOBEC3G. Nature 2008; 452:116-9. [PMID: 18288108 DOI: 10.1038/nature06638] [Citation(s) in RCA: 190] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Accepted: 12/21/2007] [Indexed: 11/08/2022]
Abstract
The human APOBEC3G (apolipoprotein B messenger-RNA-editing enzyme, catalytic polypeptide-like 3G) protein is a single-strand DNA deaminase that inhibits the replication of human immunodeficiency virus-1 (HIV-1), other retroviruses and retrotransposons. APOBEC3G anti-viral activity is circumvented by most retroelements, such as through degradation by HIV-1 Vif. APOBEC3G is a member of a family of polynucleotide cytosine deaminases, several of which also target distinct physiological substrates. For instance, APOBEC1 edits APOB mRNA and AID deaminates antibody gene DNA. Although structures of other family members exist, none of these proteins has elicited polynucleotide cytosine deaminase or anti-viral activity. Here we report a solution structure of the human APOBEC3G catalytic domain. Five alpha-helices, including two that form the zinc-coordinating active site, are arranged over a hydrophobic platform consisting of five beta-strands. NMR DNA titration experiments, computational modelling, phylogenetic conservation and Escherichia coli-based activity assays combine to suggest a DNA-binding model in which a brim of positively charged residues positions the target cytosine for catalysis. The structure of the APOBEC3G catalytic domain will help us to understand functions of other family members and interactions that occur with pathogenic proteins such as HIV-1 Vif.
Collapse
|
40
|
Kumasaka T, Yamamoto M, Furuichi M, Nakasako M, Teh AH, Kimura M, Yamaguchi I, Ueki T. Crystal structures of blasticidin S deaminase (BSD): implications for dynamic properties of catalytic zinc. J Biol Chem 2007; 282:37103-11. [PMID: 17959604 DOI: 10.1074/jbc.m704476200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The set of blasticidin S (BS) and blasticidin S deaminase (BSD) is a widely used selectable marker for gene transfer experiments. BSD is a member of the cytidine deaminase (CDA) family; it is a zinc-dependent enzyme with three cysteines and one water molecule as zinc ligands. The crystal structures of BSD were determined in six states (i.e. native, substrate-bound, product-bound, cacodylate-bound, substrate-bound E56Q mutant, and R90K mutant). In the structures, the zinc position and coordination structures vary. The substrate-bound structure shows a large positional and geometrical shift of zinc with a double-headed electron density of the substrate that seems to be assigned to the amino and hydroxyl groups of the substrate and product, respectively. In this intermediate-like structure, the steric hindrance of the hydroxyl group pushes the zinc into the triangular plane consisting of three cysteines with a positional shift of approximately 0.6 A, and the fifth ligand water approaches the opposite direction of the substrate with a shift of 0.4 A. Accordingly, the zinc coordination is changed from tetrahedral to trigonal bipyramidal, and its coordination distance is extended between zinc and its intermediate. The shift of zinc and the recruited water is also observed in the structure of the inactivated E56Q mutant. This novel observation is different in two-cysteine cytidine deaminase Escherichia coli CDA and might be essential for the reaction mechanism in BSD, since it is useful for the easy release of the product by charge compensation and for the structural change of the substrate.
Collapse
Affiliation(s)
- Takashi Kumasaka
- Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8501, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Matsubara T, Dupuis M, Aida M. Ab Initio ONIOM−Molecular Dynamics (MD) Study on the Deamination Reaction by Cytidine Deaminase. J Phys Chem B 2007; 111:9965-74. [PMID: 17661509 DOI: 10.1021/jp072732k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We applied the ONIOM-molecular dynamics (MD) method to the hydrolytic deamination of cytidine by cytidine deaminase, which is an essential step of the activation process of the anticancer drug inside the human body. The direct MD simulations were performed for the realistic model of cytidine deaminase by calculating the energy and its gradient by the ab initio ONIOM method on the fly. The ONIOM-MD calculations including the thermal motion show that the neighboring amino acid residue is an important factor of the environmental effects and significantly affects not only the geometry and energy of the substrate trapped in the pocket of the active site but also the elementary step of the catalytic reaction. We successfully simulate the second half of the catalytic cycle, which has been considered to involve the rate-determining step, and reveal that the rate-determining step is the release of the NH3 molecule.
Collapse
Affiliation(s)
- Toshiaki Matsubara
- Center for Quantum Life Sciences and Graduate School of Science, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
| | | | | |
Collapse
|
42
|
Fornili A, Sironi M, Degano M. Accurate description of nitrogenous base flexibility in classical molecular dynamics simulations of nucleotides bound to proteins. J Phys Chem B 2007; 111:6297-302. [PMID: 17508739 DOI: 10.1021/jp0713357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Proteins can induce significant distortions in planar cyclic compounds upon binding, in particular in nucleotide-enzyme complexes. An accurate representation of the ring flexibility is thus desirable when modeling these systems through classical force fields, especially when deformations are supposed to be involved in the catalytic mechanism. In this study, we use a newly developed general procedure to determine sets of dihedral parameters for planar cycles that accurately reproduce their out-of-plane normal modes as determined at the quantum mechanical (QM) level. The optimization allows the deviation from reference data to be reduced for the pyrimidine bases to values comparable to the accuracy of the QM data. Furthermore, the influence of the description of ring flexibility in protein-ligand interactions is assessed through molecular dynamics simulations of the complex between uridine and the pyrimidine-specific nucleoside hydrolase YeiK using the AMBER force field. The differences in ligand-protein interactions emerging from different parameter sets are also discussed with respect to existing biochemical data.
Collapse
|
43
|
|
44
|
Conticello SG, Langlois MA, Yang Z, Neuberger MS. DNA deamination in immunity: AID in the context of its APOBEC relatives. Adv Immunol 2007; 94:37-73. [PMID: 17560271 DOI: 10.1016/s0065-2776(06)94002-4] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The activation-induced cytidine deaminase (AID)/apolipoprotein B RNA-editing catalytic component (APOBEC) family is a vertebrate-restricted subgrouping of a superfamily of zinc (Zn)-dependent deaminases that has members distributed throughout the biological world. AID and APOBEC2 are the oldest family members with APOBEC1 and the APOBEC3s being later arrivals restricted to placental mammals. Many AID/APOBEC family members exhibit cytidine deaminase activity on polynucleotides, although in different physiological contexts. Here, we examine the AID/APOBEC proteins in the context of the entire Zn-dependent deaminase superfamily. On the basis of secondary structure predictions, we propose that the cytosine and tRNA deaminases are likely to provide better structural paradigms for the AID/APOBEC family than do the cytidine deaminases, to which they have conventionally been compared. These comparisons yield predictions concerning likely polynucleotide-interacting residues in AID/APOBEC3s, predictions that are supported by mutagenesis studies. We also focus on a specific comparison between AID and the APOBEC3s. Both are DNA deaminases that function in immunity and are responsible for the hypermutation of their target substrates. AID functions in the adaptive immune system to diversify antibodies with targeted DNA deamination being central to this function. APOBEC3s function as part of an innate pathway of immunity to retroviruses with targeted DNA deamination being central to their activity in retroviral hypermutation. However, the mechanism by which the APOBEC3s fulfill their function of retroviral restriction remains unresolved.
Collapse
Affiliation(s)
- Silvestro G Conticello
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom
| | | | | | | |
Collapse
|
45
|
Costanzi S, Vincenzetti S, Cristalli G, Vita A. Human cytidine deaminase: A three-dimensional homology model of a tetrameric metallo-enzyme inferred from the crystal structure of a distantly related dimeric homologue. J Mol Graph Model 2006; 25:10-6. [PMID: 16303324 DOI: 10.1016/j.jmgm.2005.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 07/11/2005] [Accepted: 10/19/2005] [Indexed: 10/25/2022]
Abstract
Cytidine deaminase (CDA) is a cytosolic metalloprotein whose functional unit can be either a homotetramer (T-CDA) or a homodimer (D-CDA), depending on the species. In 1994, the first crystal structure of the dimeric Escherichia coli CDA has been published. However, a crystal structure of a tetrameric CDA was not determined until 2002. Prior to the disclosure of the experimentally elucidated structure of a tetrameric CDA, we derived a homology model of the human T-CDA employing the crystal structure of the dimeric E. coli CDA as a template. The comparison of our theoretical model with the crystal structure of the human T-CDA, subsequently published in 2004, validates our prediction: not only of the structural features of the monomer and the details of the binding site, but also the multimeric arrangement of the subunits were determined with high accuracy in our model. By means of a phylogenetic analysis conducted on CDAs from various organisms, we demonstrate that the E. coli CDA is one of the furthest known homologues of the human enzyme. Nonetheless, despite the evolutionary distance and, more importantly, the different multimeric arrangement of their functional units, the E. coli CDA proved to have all the necessary information to accurately infer the structure of its human homologue.
Collapse
Affiliation(s)
- Stefano Costanzi
- Computational Chemistry Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 12A Center Drive Rm 4051 MSC 5646, Bethesda, MD 20892-0810, USA.
| | | | | | | |
Collapse
|
46
|
Matsubara T, Ishikura M, Aida M. A Quantum Chemical Study of the Catalysis for Cytidine Deaminase: Contribution of the Extra Water Molecule. J Chem Inf Model 2006; 46:1276-85. [PMID: 16711747 DOI: 10.1021/ci050479k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cytidine deaminase is known as an important enzyme responsible for the hydrolytic deamination of cytidine, which is applied as a key step to the conversion of the precursor of the cancer drug to an active form in the living body. Cytidine with water is efficiently converted to uridine with ammonia in the cleft of cytidine deaminase. In this work, the catalysis of cytidine deaminase for the hydrolytic deamination was examined using cytosine as a model of cytidine and the model molecules for the active site of cytidine deaminase by means of the quantum chemical method. We especially investigated the contribution of the water molecule from the solvent to the catalysis, because the X-ray diffraction analysis of a crystal structure has revealed the existence of the water molecule in the vicinity of the substrate bound to the active site inside the cleft. Our computations showed that the extra water molecule from the solvent has a possibility to support the catalysis of cytidine deaminase.
Collapse
Affiliation(s)
- Toshiaki Matsubara
- Center for Quantum Life Sciences and Graduate School of Science, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima 739-8530, Japan
| | | | | |
Collapse
|
47
|
Nowak I, Robins MJ. Hydrothermal Deamidation of 4-N-Acylcytosine Nucleoside Derivatives: Efficient Synthesis of Uracil Nucleoside Esters. Org Lett 2005; 7:4903-5. [PMID: 16235918 DOI: 10.1021/ol0518378] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] N,O-Peracylated cytidine and 2'-deoxycytidine derivatives in superheated water/DME solutions (oil bath at 125 degrees C) undergo hydrolytic deamidation (and/or N-deacylation). Acylated starting materials derived from arylcarboxylic acids give the corresponding uridine esters cleanly, and such derivatives crystallize selectively from the cooled reaction mixtures in high yields.
Collapse
Affiliation(s)
- Ireneusz Nowak
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-5700, USA
| | | |
Collapse
|
48
|
Elshafei AM, Ali NH, Mohamed LA. Cytidine deaminase activity inPenicillium politans NRC-510. J Basic Microbiol 2005; 45:335-43. [PMID: 16187256 DOI: 10.1002/jobm.200510575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell-free extracts of nitrate-grown Penicillium politans NRC-510 catalyzes the hydrolytic deamination of cytidine to uridine. Uridine was chromatographically identified in cell-free extracts. The enzyme exhibited optimum pH and temperature activities at 6.5 and 80 degrees C respectively. Thermal stability experiments indicated that the enzyme restored its activity at 80 degrees C for at least 60 minutes. When cell-free extracts were incubated at 90 degrees C for 5 minutes enzyme activity was inhibited by about 33%. The involvement of sulfhydryl group(s) in the catalytic site of the enzyme was shown. HgCl2 (5 x 10(-3) M) and CuSO4 (10(-2) M) caused a complete inhibition of enzyme activity. Ethylene diamine tetraacetate at a concentration of 5 x 10(-3) M and 10(-2) M inhibited the enzyme as well. Whereas, MgCl2, CoSO2 and MnCl2 had a remarkable activating effect. Dialysis of the cell-free extracts resulted to an increase in enzyme activity by about 30%. To our knowledge the thermophilic nature of the cytidine deaminase of P. politans NRC-510 is unique.
Collapse
Affiliation(s)
- Ali M Elshafei
- Department of Microbial Chemistry, National Research Centre, El-Tahrir Street, Dokki, Cairo, Egypt.
| | | | | |
Collapse
|
49
|
Guo H, Rao N, Xu Q, Guo H. Origin of tight binding of a near-perfect transition-state analogue by cytidine deaminase: implications for enzyme catalysis. J Am Chem Soc 2005; 127:3191-7. [PMID: 15740159 DOI: 10.1021/ja0439625] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cytidine deaminase (CDA) is a zinc metalloenzyme that catalyzes the hydrolytic deamination of cytidine to uridine. Zebularine (ZEB) binds to CDA, and the binding process leads to a near-perfect transition-state analogue (TSA) inhibitor at the active site with an estimated K(i) value of 1.2 x 10(-)(12) M. The interaction of CDA with the TSA inhibitor has become a paradigm for studying the tight TSA binding by enzymes. The formation of the TSA is catalyzed by CDA by a mechanism that is similar to the formation of the tetrahedral intermediate during the CDA-catalyzed reaction (i.e., through the nucleophilic attack of a Zn-hydroxide group on C(4)). It is believed that the TSA formed at the active site is zebularine 3,4-hydrate. In this paper, it is shown from QM/MM molecular dynamics and free energy simulations that zebularine 3,4-hydrate may in fact be unstable in the enzyme and that a proton transfer from the Zn-hydroxide group to Glu-104 during the nucleophilic attack could be responsible for the very high affinity. The nucleophilic attack by the Zn-hydroxide on C(4) is found to be concerted with two proton transfers. Such concerted process allows the TSA, an alkoxide-like inhibitor, to be stabilized through a mechanism that is similar to the transition-state stabilization in the general acid-base catalysis. It is suggested that the proton transfer from the Zn-hydroxide to Glu-104, which is required to generate the general acid for protonating the leaving ammonia, may play an important role in lowering the activation barrier during the catalysis.
Collapse
Affiliation(s)
- Haobo Guo
- Department of Biochemistry and Cellular and Molecular Biology, Center of Excellence in Structural Biology, University of Tennessee, Knoxville, Tennessee 37996-0840, USA.
| | | | | | | |
Collapse
|
50
|
Yao L, Sklenak S, Yan H, Cukier RI. A Molecular Dynamics Exploration of the Catalytic Mechanism of Yeast Cytosine Deaminase. J Phys Chem B 2005; 109:7500-10. [PMID: 16851861 DOI: 10.1021/jp044828+] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Yeast cytosine deaminase (yCD), a zinc metalloenzyme of significant biomedical interest, is investigated by a series of molecular dynamics simulations in its free form and complexed with its reactant (cytosine), product (uracil), several reaction intermediates, and an intermediate analogue. Quantum chemical calculations, used to construct a model for the catalytic Zn ion with its ligands (two cysteines, a histidine, and one water) show, by comparison with crystal structure data, that the cysteines are deprotonated and the histidine is monoprotonated. The simulations suggest that Glu64 plays a critical role in the catalysis by yCD. The rotation of the Glu64 side-chain carboxyl group that can be protonated or deprotonated permits it to act as a proton shuttle between the Zn-bound water and cytosine and subsequent reaction intermediates. Free energy methods are used to obtain the barriers for these rotations, and they are sufficiently small to permit rotation on a nanosecond time scale. In the course of the reaction, cytosine reorients to a geometry to favor nucleophilic attack by a Zn-bound hydroxide. A stable position for a reaction product, ammonia, was located in the active site, and the free energy of exchange with a water molecule was evaluated. The simulations also reveal small motions of the C-terminus and the loop that contains Phe114 that may be important for reactant binding and product release.
Collapse
Affiliation(s)
- Lishan Yao
- Department of Chemistry, MSU Center for Biological Modeling, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | | |
Collapse
|