1
|
Diep P, Stogios PJ, Evdokimova E, Savchenko A, Mahadevan R, Yakunin AF. Ni(II)-binding affinity of CcNikZ-II and its homologs: the role of the HH-prong and variable loop revealed by structural and mutational studies. FEBS J 2024. [PMID: 38555564 DOI: 10.1111/febs.17125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/30/2024] [Accepted: 03/13/2024] [Indexed: 04/02/2024]
Abstract
Extracytoplasmic Ni(II)-binding proteins (NiBPs) are molecular shuttles involved in cellular nickel uptake. Here, we determined the crystal structure of apo CcNikZ-II at 2.38 Å, which revealed a Ni(II)-binding site comprised of the double His (HH-)prong (His511, His512) and a short variable (v-)loop nearby (Thr59-Thr64, TEDKYT). Mutagenesis of the site identified Glu60 and His511 as critical for high affinity Ni(II)-binding. Phylogenetic analysis showed 15 protein clusters with two groups containing the HH-prong. Metal-binding assays with 11 purified NiBPs containing this feature yielded higher Ni(II)-binding affinities. Replacement of the wild type v-loop with those from other NiBPs improved the affinity by up to an order of magnitude. This work provides molecular insights into the determinants for Ni(II) affinity and paves way for NiBP engineering.
Collapse
Affiliation(s)
- Patrick Diep
- Department of Chemical Engineering and Applied Chemistry, BioZone - Centre for Applied Bioscience and Bioengineering, University of Toronto, Toronto, Ontario, Canada
- Systems & Synthetic Biology Group, Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, BioZone - Centre for Applied Bioscience and Bioengineering, University of Toronto, Toronto, Ontario, Canada
| | - Elena Evdokimova
- Department of Chemical Engineering and Applied Chemistry, BioZone - Centre for Applied Bioscience and Bioengineering, University of Toronto, Toronto, Ontario, Canada
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, BioZone - Centre for Applied Bioscience and Bioengineering, University of Toronto, Toronto, Ontario, Canada
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, BioZone - Centre for Applied Bioscience and Bioengineering, University of Toronto, Toronto, Ontario, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, BioZone - Centre for Applied Bioscience and Bioengineering, University of Toronto, Toronto, Ontario, Canada
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, Wales, UK
| |
Collapse
|
2
|
O'Brien PA, Tan S, Frade PR, Robbins SJ, Engelberts JP, Bell SC, Vanwonterghem I, Miller DJ, Webster NS, Zhang G, Bourne DG. Validation of key sponge symbiont pathways using genome-centric metatranscriptomics. Environ Microbiol 2023; 25:3207-3224. [PMID: 37732569 DOI: 10.1111/1462-2920.16509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/31/2023] [Indexed: 09/22/2023]
Abstract
The sponge microbiome underpins host function through provision and recycling of essential nutrients in a nutrient poor environment. Genomic data suggest that carbohydrate degradation, carbon fixation, nitrogen metabolism, sulphur metabolism and supplementation of B-vitamins are central microbial functions. However, validation beyond the genomic potential of sponge symbiont pathways is rarely explored. To evaluate metagenomic predictions, we sequenced the metagenomes and metatranscriptomes of three common coral reef sponges: Ircinia ramosa, Ircinia microconulosa and Phyllospongia foliascens. Multiple carbohydrate active enzymes were expressed by Poribacteria, Bacteroidota and Cyanobacteria symbionts, suggesting these lineages have a central role in assimilating dissolved organic matter. Expression of entire pathways for carbon fixation and multiple sulphur compound transformations were observed in all sponges. Gene expression for anaerobic nitrogen metabolism (denitrification and nitrate reduction) were more common than aerobic metabolism (nitrification), where only the I. ramosa microbiome expressed the nitrification pathway. Finally, while expression of the biosynthetic pathways for B-vitamins was common, the expression of additional transporter genes was far more limited. Overall, we highlight consistencies and disparities between metagenomic and metatranscriptomic results when inferring microbial activity, while uncovering new microbial taxa that contribute to the health of their sponge host via nutrient exchange.
Collapse
Affiliation(s)
- Paul A O'Brien
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Shangjin Tan
- BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China
| | | | - Steven J Robbins
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - J Pamela Engelberts
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- Centre for Microbiome Research, Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Sara C Bell
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Inka Vanwonterghem
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - David J Miller
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- Australian Antarctic Division, Department of Climate Change, Energy, Environment and Water, Kingston, Tasmania, Australia
| | - Guojie Zhang
- Centre for Evolutionary & Organismal Biology and Women's Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - David G Bourne
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
| |
Collapse
|
3
|
Huang X, Zhang X, An N, Zhang M, Ma M, Yang Y, Jing L, Wang Y, Chen Z, Zhang P. Cryo-EM structure and molecular mechanism of abscisic acid transporter ABCG25. NATURE PLANTS 2023; 9:1709-1719. [PMID: 37666961 DOI: 10.1038/s41477-023-01509-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/02/2023] [Indexed: 09/06/2023]
Abstract
Abscisic acid (ABA) is one of the plant hormones that regulate various physiological processes, including stomatal closure, seed germination and development. ABA is synthesized mainly in vascular tissues and transported to distal sites to exert its physiological functions. Many ABA transporters have been identified, however, the molecular mechanism of ABA transport remains elusive. Here we report the cryogenic electron microscopy structure of the Arabidopsis thaliana adenosine triphosphate-binding cassette G subfamily ABA exporter ABCG25 (AtABCG25) in inward-facing apo conformation, ABA-bound pre-translocation conformation and outward-facing occluded conformation. Structural and biochemical analyses reveal that the ABA bound with ABCG25 adopts a similar configuration as that in ABA receptors and that the ABA-specific binding is dictated by residues from transmembrane helices TM1, TM2 and TM5a of each protomer at the transmembrane domain interface. Comparison of different conformational structures reveals conformational changes, especially those of transmembrane helices and residues constituting the substrate translocation pathway during the cross-membrane transport process. Based on the structural data, a 'gate-flipper' translocation model of ABCG25-mediated ABA cross-membrane transport is proposed. Our structural data on AtABCG25 provide new clues to the physiological study of ABA and shed light on its potential applications in plants and agriculture.
Collapse
Affiliation(s)
- Xiaowei Huang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xue Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Ning An
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Minhua Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Miaolian Ma
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yang Yang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lianyan Jing
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yongfei Wang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Zhenguo Chen
- The Fifth People's Hospital of Shanghai, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China.
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
| |
Collapse
|
4
|
Chen D, Chen C, Guo C, Zhang H, Liang Y, Cheng Y, Qu H, Wa Y, Zhang C, Guan C, Qian J, Gu R. The regulation of simulated artificial oro-gastrointestinal transit stress on the adhesion of Lactobacillus plantarum S7. Microb Cell Fact 2023; 22:170. [PMID: 37660047 PMCID: PMC10474686 DOI: 10.1186/s12934-023-02174-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 08/09/2023] [Indexed: 09/04/2023] Open
Abstract
BACKGROUND Oro-gastrointestinal stress in the digestive tract is the main stress to which orally administered probiotics are exposed. The regulation of oro-gastrointestinal transit (OGT) stress on the adhesion and survival of probiotics under continuous exposure to simulated salivary-gastric juice-intestinal juice was researched in this study. RESULTS Lactobacillus plantarum S7 had a higher survival rate after exposure to simulated OGT1 (containing 0.15% bile salt) stress and OGT2 (containing 0.30% bile salt) stress. The adhesion ability of L. plantarum S7 was significantly increased by OGT1 stress (P < 0.05) but was not changed significantly by OGT2 stress (P > 0.05), and this trend was also observed in terms of the thickness of the surface material of L. plantarum S7 cells. The expression of surface proteins of L. plantarum S7, such as the 30 S ribosomal proteins, mucus-binding protein and S-layer protein, was significantly downregulated by OGT stress (P < 0.05); meanwhile, the expression of moonlight proteins, such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycorate kinase (PGK), beta-phosphoglucomutase (PGM1), GroEL and glucose-6-phosphate isomerase (PGI), was significantly upregulated (P < 0.05). However, the upregulation of GAPDH, PGK, PGM1 and PGI mediated by OGT1 stress was greater than those mediated by OGT2 stress. The quorum sensing pathway of L. plantarum S7 was changed significantly by OGT stress compared with no OGT stress cells (P < 0.05), and the expression of Luxs in the pathway was significantly upregulated by OGT1 stress (P < 0.05). The ABC transportation pathway was significantly altered by OGT1 stress (P < 0.05), of which the expression of the peptide ABC transporter substrate-binding protein and energy-coupling factor transporter ATP-binding protein EcfA was significantly upregulated by OGT stress (P < 0.05). The glycolide metabolism pathway was significantly altered by OGT1 stress compared with that in response to OGT2 stress (P < 0.05). CONCLUSION L. plantarum S7 had a strong ability to resist OGT stress, which was regulated by the proteins and pathways related to OGT stress. The adhesion ability of L. plantarum S7 was enhanced after continuous exposure to OGT1 stress, making it a potential probiotic with a promising future for application.
Collapse
Affiliation(s)
- Dawei Chen
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
- Jiangsu Yuhang Food Technology Co., Ltd, Yancheng, 224000, Jiangsu, China
| | - Chunmeng Chen
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Congcong Guo
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Hui Zhang
- Yangzhou Hospital of Traditional Chinese Medicine, Yangzhou, 225127, Jiangsu, China
| | - Yating Liang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Yue Cheng
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Hengxian Qu
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Yunchao Wa
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Chenchen Zhang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Chengran Guan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Jianya Qian
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China
| | - Ruixia Gu
- College of Food Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China.
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, 225127, Jiangsu, China.
| |
Collapse
|
5
|
Lee SM, Kim N, Yoon H, Kim YS, Choi SI, Park JH, Lee DH. Compositional and Functional Changes in the Gut Microbiota in Irritable Bowel Syndrome Patients. Gut Liver 2021; 15:253-261. [PMID: 32457278 PMCID: PMC7960967 DOI: 10.5009/gnl19379] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 02/29/2020] [Accepted: 03/23/2020] [Indexed: 12/12/2022] Open
Abstract
Background/Aims This study aimed to characterize the changes in the gut microbiota of irritable bowel syndrome (IBS) patients and to investigate the consequent alterations in bacterial functions. Methods We performed 16S rRNA metagenomic sequencing and a phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analyses using fecal samples from control (n=12) and diarrhea-dominant IBS patients (n=7). Results The samples were clustered by the principal coordinates analysis depending on the presence of IBS (p=0.003). In the IBS patients, the abundances of Acidaminococcaceae, Sutterellaceae, and Desulfovibrionaceae were significantly increased, while those of Enterococcaceae, Leuconostocaceae, Clostridiaceae, Peptostreptococcaceae, and Lachnospiraceae were significantly decreased. The PICRUSt results indicated that two orthologues involved in secondary bile acid biosynthesis were significantly decreased in IBS patients. Modules involved in multidrug resistance, lipopolysaccharide biosynthesis, the reductive citrate cycle, and the citrate cycle were significantly increased in the IBS patients. In contrast, modules involved in cationic antimicrobial peptide resistance, and some transport systems were more abundant in controls than in IBS patients. Conclusions Changes in the gut microbiota composition in IBS patients lead to alterations in bacterial functions, such as bile acid transformation and the induction of inflammation, which is a known pathophysiological mechanism of IBS.
Collapse
Affiliation(s)
- Sun Min Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Nayoung Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Hyuk Yoon
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Yong Sung Kim
- Digestive Disease Research Institute, Wonkwang University, Iksan, Korea.,DCNbio, Seongnam, Korea
| | - Soo In Choi
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Ji Hyun Park
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Dong Ho Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| |
Collapse
|
6
|
Finkenwirth F, Sippach M, Pecina SN, Gäde M, Ruta J, Ricke A, Bondarenko E, Klare JP, Zinke M, Lange S, Lange A, Steinhoff HJ, Eitinger T. Dynamic interactions of CbiN and CbiM trigger activity of a cobalt energy-coupling-factor transporter. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183114. [PMID: 31666178 DOI: 10.1016/j.bbamem.2019.183114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/01/2019] [Accepted: 10/08/2019] [Indexed: 11/26/2022]
Abstract
Energy-coupling factor (ECF) transporters for uptake of vitamins and transition-metal ions into prokaryotic cells share a common architecture consisting of a substrate-specific integral membrane protein (S), a transmembrane coupling protein (T) and two cytoplasmic ATP-binding-cassette-family ATPases. S components rotate within the membrane to expose their binding pockets alternately to the exterior and the cytoplasm. In contrast to vitamin transporters, metal-specific systems rely on additional proteins with essential but poorly understood functions. CbiN, a membrane protein composed of two transmembrane helices tethered by an extracytoplasmic loop of 37 amino-acid residues represents the auxiliary component that temporarily interacts with the CbiMQO2 Co2+ transporter. CbiN was previously shown to induce significant Co2+ transport activity in the absence of CbiQO2 in cells producing the S component CbiM plus CbiN or a Cbi(MN) fusion. Here we analyzed the mode of interaction between the two protein domains. Any deletion in the CbiN loop abolished transport activity. In silico predicted protein-protein contacts between segments of the CbiN loop and loops in CbiM were confirmed by cysteine-scanning mutagenesis and crosslinking. Likewise, an ordered structure of the CbiN loop was observed by electron paramagnetic resonance analysis after site-directed spin labeling. The N-terminal loop of CbiM containing three of four metal ligands was partially immobilized in wild-type Cbi(MN) but completely immobile in inactive variants with CbiN loop deletions. Decreased dynamics of the inactive form was also detected by solid-state nuclear magnetic resonance of isotope-labeled protein in proteoliposomes. In conclusion, CbiM-CbiN loop-loop interactions facilitate metal insertion into the binding pocket.
Collapse
Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Michael Sippach
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Sinah N Pecina
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Mario Gäde
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Julia Ruta
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Adrian Ricke
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Elena Bondarenko
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Johann P Klare
- Fachbereich Physik, Universität Osnabrück, 49076 Osnabrück, Germany
| | - Maximilian Zinke
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Sascha Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Adam Lange
- Department of Molecular Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany; Institut für Biologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | | | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10099 Berlin, Germany.
| |
Collapse
|
7
|
Tamura K, Sugimoto H, Shiro Y, Sugita Y. Chemo-Mechanical Coupling in the Transport Cycle of a Heme ABC Transporter. J Phys Chem B 2019; 123:7270-7281. [PMID: 31362510 DOI: 10.1021/acs.jpcb.9b04356] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The heme importer from pathogenic bacteria is a member of the ATP-binding cassette (ABC) transporter family, which uses the energy of ATP-binding and hydrolysis for extensive conformational changes. Previous studies have indicated that conformational changes after heme translocation are triggered by ATP-binding to nucleotide binding domains (NBDs) and then, in turn, induce conformational transitions of the transmembrane domains (TMDs). In this study, we applied a template-based iterative all-atom molecular dynamics (MD) simulation to predict the ATP-bound outward-facing conformation of the Burkholderia cenocepacia heme importer BhuUV-T. The resulting model showed a stable conformation of the TMD with the cytoplasmic gate in the closed state and the periplasmic gate in the open state. Furthermore, targeted MD simulation predicted the intermediate structure of an occluded form (Occ) with bound ATP, in which both ends of the heme translocation channel are closed. The MD simulation of the predicted Occ revealed that Ser147 on the ABC signature motifs (LSGG[Q/E]) of NBDs occasionally flips and loses the active conformation required for ATP-hydrolysis. The flipping motion was found to be coupled to the inter-NBD distance. Our results highlight the functional significance of the signature motif of ABC transporters in regulation of ATPase and chemo-mechanical coupling mechanism.
Collapse
Affiliation(s)
- Koichi Tamura
- Computational Biophysics Research Team , RIKEN Center for Computational Science , 6-7-1 minatojima-Minamimachi, Chuo-ku , Kobe , Hyogo 650-0047 , Japan
| | - Hiroshi Sugimoto
- Graduate School of Life Science , University of Hyogo , 3-2-1 Kouto, Kamigori , Ako , Hyogo 678-1297 , Japan.,Synchrotron Radiation Life Science Instrumentation Team , RIKEN SPring-8 Center , 1-1-1 Kouto , Sayo , Hyogo 679-5148 , Japan
| | - Yoshitsugu Shiro
- Graduate School of Life Science , University of Hyogo , 3-2-1 Kouto, Kamigori , Ako , Hyogo 678-1297 , Japan
| | - Yuji Sugita
- Computational Biophysics Research Team , RIKEN Center for Computational Science , 6-7-1 minatojima-Minamimachi, Chuo-ku , Kobe , Hyogo 650-0047 , Japan.,Theoretical Molecular Science Laboratory , RIKEN Cluster for Pioneering Research , 2-1 Hirosawa , Wako , Saitama 351-0198 , Japan.,Laboratory for Biomolecular Function Simulation , RIKEN Center for Biosystems Dynamics Research , 6-7-1 minatojima-Minamimachi, Chuo-ku , Kobe , Hyogo 650-0047 , Japan
| |
Collapse
|
8
|
Finkenwirth F, Eitinger T. ECF-type ABC transporters for uptake of vitamins and transition metal ions into prokaryotic cells. Res Microbiol 2019; 170:358-365. [PMID: 31283960 DOI: 10.1016/j.resmic.2019.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/27/2019] [Accepted: 06/29/2019] [Indexed: 12/15/2022]
Abstract
Energy-coupling factor (ECF) transporters mediate the uptake of micronutrients in prokaryotes. They consist of two ATP-binding-cassette family ATPases, a transmembrane coupling protein (T component) and a substrate-binding membrane protein (S component). ECF transporters for Co2+ and Ni2+ ions have one or two additional proteins with extracytoplasmic regions but poorly understood function. Homologs of T components with a predicted localization in plastids are widespread in plants but their physiological role is unclear. S components in eukaryotes are very rare and restricted to biotin-specific variants. Apart from a potential contribution to the export of flavins to serve the assembly of extracytoplasmic electron transfer chains, ECF transporters function as importers.
Collapse
Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
| |
Collapse
|
9
|
Abstract
Nickel is an essential cofactor for some pathogen virulence factors. Due to its low availability in hosts, pathogens must efficiently transport the metal and then balance its ready intracellular availability for enzyme maturation with metal toxicity concerns. The most notable virulence-associated components are the Ni-enzymes hydrogenase and urease. Both enzymes, along with their associated nickel transporters, storage reservoirs, and maturation enzymes have been best-studied in the gastric pathogen Helicobacter pylori, a bacterium which depends heavily on nickel. Molecular hydrogen utilization is associated with efficient host colonization by the Helicobacters, which include both gastric and liver pathogens. Translocation of a H. pylori carcinogenic toxin into host epithelial cells is powered by H2 use. The multiple [NiFe] hydrogenases of Salmonella enterica Typhimurium are important in host colonization, while ureases play important roles in both prokaryotic (Proteus mirabilis and Staphylococcus spp.) and eukaryotic (Cryptoccoccus genus) pathogens associated with urinary tract infections. Other Ni-requiring enzymes, such as Ni-acireductone dioxygenase (ARD), Ni-superoxide dismutase (SOD), and Ni-glyoxalase I (GloI) play important metabolic or detoxifying roles in other pathogens. Nickel-requiring enzymes are likely important for virulence of at least 40 prokaryotic and nine eukaryotic pathogenic species, as described herein. The potential for pathogenic roles of many new Ni-binding components exists, based on recent experimental data and on the key roles that Ni enzymes play in a diverse array of pathogens.
Collapse
|
10
|
Hofmann JD, Otto A, Berges M, Biedendieck R, Michel AM, Becher D, Jahn D, Neumann-Schaal M. Metabolic Reprogramming of Clostridioides difficile During the Stationary Phase With the Induction of Toxin Production. Front Microbiol 2018; 9:1970. [PMID: 30186274 PMCID: PMC6110889 DOI: 10.3389/fmicb.2018.01970] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/03/2018] [Indexed: 12/20/2022] Open
Abstract
The obligate anaerobe, spore forming bacterium Clostridioides difficile (formerly Clostridium difficile) causes nosocomial and community acquired diarrhea often associated with antibiotic therapy. Major virulence factors of the bacterium are the two large clostridial toxins TcdA and TcdB. The production of both toxins was found strongly connected to the metabolism and the nutritional status of the growth environment. Here, we systematically investigated the changes of the gene regulatory, proteomic and metabolic networks of C. difficile 630Δerm underlying the adaptation to the non-growing state in the stationary phase. Integrated data from time-resolved transcriptome, proteome and metabolome investigations performed under defined growth conditions uncovered multiple adaptation strategies. Overall changes in the cellular processes included the downregulation of ribosome production, lipid metabolism, cold shock proteins, spermine biosynthesis, and glycolysis and in the later stages of riboflavin and coenzyme A (CoA) biosynthesis. In contrast, different chaperones, several fermentation pathways, and cysteine, serine, and pantothenate biosynthesis were found upregulated. Focusing on the Stickland amino acid fermentation and the central carbon metabolism, we discovered the ability of C. difficile to replenish its favored amino acid cysteine by a pathway starting from the glycolytic 3-phosphoglycerate via L-serine as intermediate. Following the growth course, the reductive equivalent pathways used were sequentially shifted from proline via leucine/phenylalanine to the central carbon metabolism first to butanoate fermentation and then further to lactate fermentation. The toxin production was found correlated mainly to fluxes of the central carbon metabolism. Toxin formation in the supernatant was detected when the flux changed from butanoate to lactate synthesis in the late stationary phase. The holistic view derived from the combination of transcriptome, proteome and metabolome data allowed us to uncover the major metabolic strategies that are used by the clostridial cells to maintain its cellular homeostasis and ensure survival under starvation conditions.
Collapse
Affiliation(s)
- Julia D Hofmann
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Andreas Otto
- Department for Microbial Proteomics, University of Greifswald, Greifswald, Germany
| | - Mareike Berges
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Annika-Marisa Michel
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Dörte Becher
- Department for Microbial Proteomics, University of Greifswald, Greifswald, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| |
Collapse
|
11
|
Biotin-mediated growth and gene expression in Staphylococcus aureus is highly responsive to environmental biotin. Appl Microbiol Biotechnol 2018; 102:3793-3803. [PMID: 29508030 DOI: 10.1007/s00253-018-8866-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/11/2018] [Accepted: 02/12/2018] [Indexed: 10/17/2022]
Abstract
Biotin (Vitamin B7) is a critical enzyme co-factor in metabolic pathways important for bacterial survival. Biotin is obtained either from the environment or by de novo synthesis, with some bacteria capable of both. In certain species, the bifunctional protein BirA plays a key role in biotin homeostasis as it regulates expression of biotin biosynthetic enzymes in response to biotin demand and supply. Here, we compare the effect of biotin on the growth of two bacteria that possess a bifunctional BirA, namely Escherichia coli and Staphylococcus aureus. Unlike E. coli that could fulfill its biotin requirements through de novo synthesis, S. aureus showed improved growth rates in media supplemented with 10 nM biotin. S. aureus also accumulated more radiolabeled biotin from the media highlighting its ability to efficiently scavenge exogenous material. These data are consistent with S. aureus colonizing low biotin microhabitats. We also demonstrate that the S. aureus BirA protein is a transcriptional repressor of BioY, a subunit of the biotin transporter, and an operon containing yhfT and yhfS, the products of which have a putative role in fatty acid homeostasis. Increased expression of bioY is proposed to help cue S. aureus for efficient scavenging in low biotin environments.
Collapse
|
12
|
Crystal Structure of a Group I Energy Coupling Factor Vitamin Transporter S Component in Complex with Its Cognate Substrate. Cell Chem Biol 2017; 23:827-836. [PMID: 27447050 PMCID: PMC5037267 DOI: 10.1016/j.chembiol.2016.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/18/2016] [Accepted: 06/02/2016] [Indexed: 12/27/2022]
Abstract
Energy coupling factor (ECF) transporters are responsible for the uptake of essential scarce nutrients in prokaryotes. This ATP-binding cassette transporter family comprises two subgroups that share a common architecture forming a tripartite membrane protein complex consisting of a translocation component and ATP hydrolyzing module and a substrate-capture (S) component. Here, we present the crystal structure of YkoE from Bacillus subtilis, the S component of the previously uncharacterized group I ECF transporter YkoEDC. Structural and biochemical analyses revealed the constituent residues of the thiamine-binding pocket as well as an unexpected mode of vitamin recognition. In addition, our experimental and bioinformatics data demonstrate major differences between YkoE and group II ECF transporters and indicate how group I vitamin transporter S components have diverged from other group I and group II ECF transporters. The crystal structure of a group I ECF transporter S component was determined The thiamine-bound structure was determined in lipidic environment The structure reveals major differences to group II S components CGMD simulations indicate the orientation of the protein in the membrane
Collapse
|
13
|
Finkenwirth F, Kirsch F, Eitinger T. Complex Stability During the Transport Cycle of a Subclass I ECF Transporter. Biochemistry 2017; 56:4578-4583. [DOI: 10.1021/acs.biochem.7b00390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Friedrich Finkenwirth
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Franziska Kirsch
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Thomas Eitinger
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| |
Collapse
|
14
|
Locher KP. Mechanistic diversity in ATP-binding cassette (ABC) transporters. Nat Struct Mol Biol 2017; 23:487-93. [PMID: 27273632 DOI: 10.1038/nsmb.3216] [Citation(s) in RCA: 511] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 03/30/2016] [Indexed: 12/18/2022]
Abstract
ABC transporters catalyze transport reactions, such as the high-affinity uptake of micronutrients into bacteria and the export of cytotoxic compounds from mammalian cells. Crystal structures of ABC domains and full transporters have provided a framework for formulating reaction mechanisms of ATP-driven substrate transport, but recent studies have suggested remarkable mechanistic diversity within this protein family. This review evaluates the differing mechanistic proposals and outlines future directions for the exploration of ABC-transporter-catalyzed reactions.
Collapse
Affiliation(s)
- Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
15
|
Structure and mechanism of a group-I cobalt energy coupling factor transporter. Cell Res 2017; 27:675-687. [PMID: 28322252 DOI: 10.1038/cr.2017.38] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/08/2017] [Accepted: 02/15/2017] [Indexed: 12/20/2022] Open
Abstract
Energy-coupling factor (ECF) transporters are a large family of ATP-binding cassette transporters recently identified in microorganisms. Responsible for micronutrient uptake from the environment, ECF transporters are modular transporters composed of a membrane substrate-binding component EcfS and an ECF module consisting of an integral membrane scaffold component EcfT and two cytoplasmic ATP binding/hydrolysis components EcfA/A'. ECF transporters are classified into groups I and II. Currently, the molecular understanding of group-I ECF transporters is very limited, partly due to a lack of transporter complex structural information. Here, we present structures and structure-based analyses of the group-I cobalt ECF transporter CbiMNQO, whose constituting subunits CbiM/CbiN, CbiQ, and CbiO correspond to the EcfS, EcfT, and EcfA components of group-II ECF transporters, respectively. Through reconstitution of different CbiMNQO subunits and determination of related ATPase and transporter activities, the substrate-binding subunit CbiM was found to stimulate CbiQO's basal ATPase activity. The structure of CbiMQO complex was determined in its inward-open conformation and that of CbiO in β, γ-methyleneadenosine 5'-triphosphate-bound closed conformation. Structure-based analyses revealed interactions between different components, substrate-gating function of the L1 loop of CbiM, and conformational changes of CbiO induced by ATP binding and product release within the CbiMNQO transporter complex. These findings enabled us to propose a working model of the CbiMNQO transporter, in which the transport process requires the rotation or toppling of both CbiQ and CbiM, and CbiN might function in coupling conformational changes between CbiQ and CbiM.
Collapse
|
16
|
Lewinson O, Livnat-Levanon N. Mechanism of Action of ABC Importers: Conservation, Divergence, and Physiological Adaptations. J Mol Biol 2017; 429:606-619. [PMID: 28104364 DOI: 10.1016/j.jmb.2017.01.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/08/2023]
Abstract
The past decade has seen a remarkable surge in structural characterization of ATP binding cassette (ABC) transporters, which have spurred a more focused functional analysis of these elaborate molecular machines. As a result, it has become increasingly apparent that there is a substantial degree of mechanistic variation between ABC transporters that function as importers, which correlates with their physiological roles. Here, we summarize recent advances in ABC importers' structure-function studies and provide an explanation as to the origin of the different mechanisms of action.
Collapse
Affiliation(s)
- Oded Lewinson
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel.
| | - Nurit Livnat-Levanon
- Department of Biochemistry, The Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, 31096 Haifa, Israel
| |
Collapse
|
17
|
Karpowich NK, Song J, Wang DN. An Aromatic Cap Seals the Substrate Binding Site in an ECF-Type S Subunit for Riboflavin. J Mol Biol 2016; 428:3118-30. [PMID: 27312125 DOI: 10.1016/j.jmb.2016.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/07/2016] [Accepted: 06/07/2016] [Indexed: 10/21/2022]
Abstract
ECF transporters are a family of active membrane transporters for essential micronutrients, such as vitamins and trace metals. Found exclusively in archaea and bacteria, these transporters are composed of four subunits: an integral membrane substrate-binding subunit (EcfS), a transmembrane coupling subunit (EcfT), and two ATP-binding cassette ATPases (EcfA and EcfA'). We have characterized the structural basis of substrate binding by the EcfS subunit for riboflavin from Thermotoga maritima, TmRibU. TmRibU binds riboflavin with high affinity, and the protein-substrate complex is exceptionally stable in solution. The crystal structure of riboflavin-bound TmRibU reveals an electronegative binding pocket at the extracellular surface in which the substrate is completely buried. Analysis of the intermolecular contacts indicates that nearly every available substrate hydrogen bond is satisfied. A conserved aromatic residue at the extracellular end of TM5, Tyr130, caps the binding site to generate a substrate-bound, occluded state, and non-conservative mutation of Tyr130 reduces the stability of this conformation. Using a novel fluorescence binding assay, we find that an aromatic residue at this position is essential for high-affinity substrate binding. Comparison with other S subunit structures suggests that TM5 and Loop5-6 contain a dynamic, conserved motif that plays a key role in gating substrate entry and release by S subunits of ECF transporters.
Collapse
Affiliation(s)
- Nathan K Karpowich
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
| | - Jinmei Song
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Da-Neng Wang
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
| |
Collapse
|
18
|
Abstract
Nickel supports the growth of microbes from a variety of very different growth environments that affect nickel speciation. The mechanisms of nickel uptake and the molecular bases for the selectivity of this process are emerging. The recent surge of Ni-importer protein structures provides an understanding of Ni-recognition in the initial binding step of the import process. This review compares the structural basis for Ni-recognition in the complexes (ABC and ECF-type) that dominate primary (ATP-dependent) transport, with a focus on how the structures suggest mechanisms for Ni selectivity. The structures raise key questions about the mechanisms of nickel-transfer reactions involved in import. There is also a discussion of key experimental approaches necessary to help establish the physiological importance of these structures.
Collapse
Affiliation(s)
- Peter T Chivers
- Department of Chemistry and School of Biological and Biomedical Sciences, Durham University, Durham, UK.
| |
Collapse
|
19
|
Zollmann T, Bock C, Graab P, Abele R. Team work at its best – TAPL and its two domains. Biol Chem 2015; 396:967-74. [DOI: 10.1515/hsz-2014-0319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/20/2015] [Indexed: 11/15/2022]
Abstract
Abstract
The transporter associated with antigen processing (TAPL, ABCB9) is a homodimeric ABC transporter, shuttling cytosolic polypeptides into the lumen of lysosomes energized by ATP hydrolysis. Here we give a short overview of the superfamily of ABC transporters and summarize the current state of knowledge on TAPL in detail. The architecture of TAPL and its substrate specificity are described and we discuss the function of an extra N-terminal transmembrane domain, called TMD0, in respect of subcellular targeting and interaction with proteins, contributing to long-term stability. As TAPL shows – besides a ubiquitous basal expression – an elevated expression in antigen presenting cells, we present models of TAPL function in adaptive immunity.
Collapse
|
20
|
Zhao Q, Wang C, Wang C, Guo H, Bao Z, Zhang M, Zhang P. Structures of FolT in substrate-bound and substrate-released conformations reveal a gating mechanism for ECF transporters. Nat Commun 2015. [PMID: 26198469 PMCID: PMC4525288 DOI: 10.1038/ncomms8661] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Energy-coupling factor (ECF) transporters are a new family of ABC transporters that consist of four subunits, two cytoplasmic ATPases EcfA and EcfA' and two transmembrane proteins namely EcfS for substrate-specific binding and EcfT for energy coupling. Here, we report the 3.2-Å resolution crystal structure of the EcfS protein of a folate ECF transporter from Enterococcus faecalis-EfFolT, a close homologue of FolT from Lactobacillus brevis-LbFolT. Structural and biochemical analyses reveal the residues constituting the folate-binding pocket and determining the substrate-binding specificity. Structural comparison of the folate-bound EfFolT with the folate-free LbFolT contained in the holotransporter complex discloses significant conformational change at the L1 loop, and reveals a gating mechanism of ECF transporters in which the L1 loop of EcfS acts as a gate in the substrate binding and release. Substrate specificity of ECF transporters is determined by the transmembrane EcfS protein subunit. Here Zhao et al. present substrate-bound and substrate-released structures of a bacterial folate transporter EcfS and suggest a gating mechanism for ECF transporters.
Collapse
Affiliation(s)
- Qin Zhao
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chengcheng Wang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chengyuan Wang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Hui Guo
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhihao Bao
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Minhua Zhang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| |
Collapse
|
21
|
Pyridoxamine is a substrate of the energy-coupling factor transporter HmpT. Cell Discov 2015; 1:15014. [PMID: 27462413 PMCID: PMC4860826 DOI: 10.1038/celldisc.2015.14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/28/2015] [Indexed: 12/12/2022] Open
Abstract
Energy-coupling factor (ECF) transporters belong to a novel family of proteins that forms a subset within the ATP-binding cassette (ABC) transporter family. These proteins are responsible for the uptake of micronutrients in bacteria. ECF transporters are composed of four proteins: the A- and A′-components, the T-component and the S-component. One of the ECF transporters, named HmpT, was crystallized in the apo form with all four components. It is currently unknown whether HmpT serves as a transporter for hydroxymethyl pyrimidine or the different forms of vitamin B6 (pyridoxine, pyridoxal or pyridoxamine). Using a combination of molecular dynamics (MD) simulations and mass spectrometry, we have identified pyridoxamine to be the preferred substrate of HmpT. Mass spectra show that the mass of the substrate from the HmpT–substrate complex matches that of pyridoxamine. MD simulations likewise indicate that pyridoxamine interacts most strongly with most of the conserved residues of the S-component (Glu 41, His 84 and Gln 43) compared with the other vitamin B6 forms. Furthermore, the simulations have implied that loops 1 and 5 of the S-component can participate in the gating action for HmpT.
Collapse
|
22
|
ATP binding drives substrate capture in an ECF transporter by a release-and-catch mechanism. Nat Struct Mol Biol 2015; 22:565-71. [PMID: 26052893 PMCID: PMC4634891 DOI: 10.1038/nsmb.3040] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 05/05/2015] [Indexed: 01/07/2023]
Abstract
ECF transporters are a family of active transporters for vitamins. They are composed of four subunits: a membrane-embedded substrate-binding subunit (EcfS), a transmembrane coupling subunit (EcfT) and two ATP-binding-cassette ATPases (EcfA and EcfA'). We have investigated the mechanism of the ECF transporter for riboflavin from the pathogen Listeria monocytogenes, LmECF-RibU. Using structural and biochemical approaches, we found that ATP binding to the EcfAA' ATPases drives a conformational change that dissociates the S subunit from the EcfAA'T ECF module. Upon release from the ECF module, the RibU S subunit then binds the riboflavin transport substrate. We also find that S subunits for distinct substrates compete for the ATP-bound state of the ECF module. Our results explain how ECF transporters capture the transport substrate and reproduce the in vivo observations on S-subunit competition for which the family was named.
Collapse
|
23
|
Finkenwirth F, Sippach M, Landmesser H, Kirsch F, Ogienko A, Grunzel M, Kiesler C, Steinhoff HJ, Schneider E, Eitinger T. ATP-dependent Conformational Changes Trigger Substrate Capture and Release by an ECF-type Biotin Transporter. J Biol Chem 2015; 290:16929-42. [PMID: 25991724 DOI: 10.1074/jbc.m115.654343] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Indexed: 11/06/2022] Open
Abstract
Energy-coupling factor (ECF) transporters for vitamins and metal ions in prokaryotes consist of two ATP-binding cassette-type ATPases, a substrate-specific transmembrane protein (S component) and a transmembrane protein (T component) that physically interacts with the ATPases and the S component. The mechanism of ECF transporters was analyzed upon reconstitution of a bacterial biotin transporter into phospholipid bilayer nanodiscs. ATPase activity was not stimulated by biotin and was only moderately reduced by vanadate. A non-hydrolyzable ATP analog was a competitive inhibitor. As evidenced by cross-linking of monocysteine variants and by site-specific spin labeling of the Q-helix followed by EPR-based interspin distance analyses, closure and reopening of the ATPase dimer (BioM2) was a consequence of ATP binding and hydrolysis, respectively. A previously suggested role of a stretch of small hydrophobic amino acid residues within the first transmembrane segment of the S units for S unit/T unit interactions was structurally and functionally confirmed for the biotin transporter. Cross-linking of this segment in BioY (S) using homobifunctional thiol-reactive reagents to a coupling helix of BioN (T) indicated a reorientation rather than a disruption of the BioY/BioN interface during catalysis. Fluorescence emission of BioY labeled with an environmentally sensitive fluorophore was compatible with an ATP-induced reorientation and consistent with a hypothesized toppling mechanism. As demonstrated by [(3)H]biotin capture assays, ATP binding stimulated substrate capture by the transporter, and subsequent ATP hydrolysis led to substrate release. Our study represents the first experimental insight into the individual steps during the catalytic cycle of an ECF transporter in a lipid environment.
Collapse
Affiliation(s)
| | - Michael Sippach
- the Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany
| | - Heidi Landmesser
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and
| | | | | | | | | | - Heinz-Jürgen Steinhoff
- the Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany
| | - Erwin Schneider
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and
| | | |
Collapse
|
24
|
Structure of a pantothenate transporter and implications for ECF module sharing and energy coupling of group II ECF transporters. Proc Natl Acad Sci U S A 2014; 111:18560-5. [PMID: 25512487 DOI: 10.1073/pnas.1412246112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Energy-coupling factor (ECF) transporters are a unique group of ATP-binding cassette (ABC) transporters responsible for micronutrient uptake from the environment. Each ECF transporter is composed of an S component (or EcfS protein) and T/A/A' components (or EcfT/A/A' proteins; ECF module). Among the group II ECF transporters, several EcfS proteins share one ECF module; however, the underlying mechanism remains unknown. Here we report the structure of a group II ECF transporter-pantothenate transporter from Lactobacillus brevis (LbECF-PanT), which shares the ECF module with the folate and hydroxymethylpyrimidine transporters (LbECF-FolT and LbECF-HmpT). Structural and mutational analyses revealed the residues constituting the pantothenate-binding pocket. We found that although the three EcfS proteins PanT, FolT, and HmpT are dissimilar in sequence, they share a common surface area composed of the transmembrane helices 1/2/6 (SM1/2/6) to interact with the coupling helices 2/3 (CH2/3) of the same EcfT. CH2 interacts mainly with SM1 via hydrophobic interactions, which may modulate the sliding movement of EcfS. CH3 binds to a hydrophobic surface groove formed by SM1, SM2, and SM6, which may transmit the conformational changes from EcfA/A' to EcfS. We also found that the residues at the intermolecular surfaces in LbECF-PanT are essential for transporter activity, and that these residues may mediate intermolecular conformational transmission and/or affect transporter complex stability. In addition, we found that the structure of EcfT is conformationally dynamic, which supports its function as a scaffold to mediate the interaction of the ECF module with various EcfS proteins to form different transporter complexes.
Collapse
|
25
|
Almagor L, Giladi M, van Dijk L, Buki T, Hiller R, Khananshvili D. Functional asymmetry of bidirectional Ca2+-movements in an archaeal sodium-calcium exchanger (NCX_Mj). Cell Calcium 2014; 56:276-84. [PMID: 25218934 DOI: 10.1016/j.ceca.2014.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/11/2014] [Accepted: 08/20/2014] [Indexed: 11/25/2022]
Abstract
Dynamic features of Ca(2+) interactions with transport and regulatory sites control the Ca(2+)-fluxes in mammalian Na(+)/Ca(2+)(NCX) exchangers bearing the Ca(2+)-binding regulatory domains on the cytosolic 5L6 loop. The crystal structure of Methanococcus jannaschii NCX (NCX_Mj) may serve as a template for studying ion-transport mechanisms since NCX_Mj does not contain the regulatory domains. The turnover rate of Na(+)/Ca(2+) exchange (kcat=0.5±0.2 s(-1)) in WT-NCX_Mj is 10(3)-10(4) times slower than in mammalian NCX. In NCX_Mj, the intrinsic equilibrium (Kint) for bidirectional Ca(2+) movements (defined as the ratio between the cytosolic and extracellular Km of Ca(2+)/Ca(2+) exchange) is asymmetric, Kint=0.15±0.5. Therefore, the Ca(2+) movement from the cytosol to the extracellular side is ∼7-times faster than in the opposite direction, thereby representing a stabilization of outward-facing (extracellular) access. This intrinsic asymmetry accounts for observed differences in the cytosolic and extracellulr Km values having a physiological relevance. Bidirectional Ca(2+) movements are also asymmetric in mammalian NCX. Thus, the stabilization of the outward-facing access along the transport cycle is a common feature among NCX orthologs despite huge differences in the ion-transport kinetics. Elongation of the cytosolic 5L6 loop in NCX_Mj by 8 or 14 residues accelerates the ion transport rates (kcat) ∼10 fold, while increasing the Kint values 100-250-fold (Kint=15-35). Therefore, 5L6 controls both the intrinsic equilibrium and rates of bidirectional Ca(2+) movements in NCX proteins. Some additional structural elements may shape the kinetic variances among phylogenetically distant NCX variants, although the intrinsic asymmetry (Kint) of bidirectional Ca(2+) movements seems to be comparable among evolutionary diverged NCX variants.
Collapse
Affiliation(s)
- Lior Almagor
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv 69978, Israel
| | - Moshe Giladi
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv 69978, Israel
| | - Liat van Dijk
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv 69978, Israel
| | - Tal Buki
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv 69978, Israel
| | - Reuben Hiller
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv 69978, Israel
| | - Daniel Khananshvili
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv 69978, Israel.
| |
Collapse
|
26
|
Abstract
ATP-binding cassette transporters are multi-subunit membrane pumps that transport substrates across membranes. While significant in the transport process, transporter architecture exhibits a range of diversity that we are only beginning to recognize. This divergence may provide insight into the mechanisms of substrate transport and homeostasis. Until recently, ABC importers have been classified into two types, but with the emergence of energy-coupling factor (ECF) transporters there are potentially three types of ABC importers. In this review, we summarize an expansive body of research on the three types of importers with an emphasis on the basics that underlie ABC importers, such as structure, subunit composition and mechanism.
Collapse
Affiliation(s)
- Austin J Rice
- Department of Molecular Biosciences, Northwestern University , Evanston, IL , USA
| | | | | |
Collapse
|
27
|
Kirsch F, Eitinger T. Transport of nickel and cobalt ions into bacterial cells by S components of ECF transporters. Biometals 2014; 27:653-60. [PMID: 24781825 DOI: 10.1007/s10534-014-9738-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 04/13/2014] [Indexed: 10/25/2022]
Abstract
Energy-coupling factor (ECF) transporters form a distinct group of ABC-type micronutrient importers in prokaryotes that do not contain extracytoplasmic, soluble substrate-binding proteins. Instead, they consist of a transmembrane substrate-specific S component that interacts with a module composed of a moderately conserved transmembrane (T) component and ABC ATPases. The majority of S components is considered to act as high-affinity binding proteins that strictly depend on their cognate T and ATPase units for transport activity. For a fraction of biotin-specific S units, however, transport activity was demonstrated in their solitary state. Here, we compared the activities of nickel- and cobalt-specific ECF transporters in the presence and absence of their T and ATPase units. Accumulation assays with radioactive metal ions showed that the truncated transporters led to approx. 25% of cell-bound radioactivity compared to the holotransporters. Activity of urease, an intracellular nickel-dependent enzyme, was used as a reporter and clearly indicated that the cell-bound radioactivity correlates with the cytoplasmic metal concentration. The results demonstrate that S units of metal transporters not only bind their substrates on the cell surface but mediate transport across the membrane, a finding of general importance on the way to understand the mechanism of ECF transporters.
Collapse
Affiliation(s)
- Franziska Kirsch
- Humboldt-Universität zu Berlin, Institut für Biologie/Mikrobiologie, Chausseestraße 117, 10115, Berlin, Germany
| | | |
Collapse
|
28
|
Abstract
ATP-binding cassette (ABC) transporters form a large superfamily of ATP-dependent protein complexes that mediate transport of a vast array of substrates across membranes. The 14 currently available structures of ABC transporters have greatly advanced insight into the transport mechanism and revealed a tremendous structural diversity. Whereas the domains that hydrolyze ATP are structurally related in all ABC transporters, the membrane-embedded domains, where the substrates are translocated, adopt four different unrelated folds. Here, we review the structural characteristics of ABC transporters and discuss the implications of this structural diversity for mechanistic diversity.
Collapse
Affiliation(s)
- Josy ter Beek
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, Netherlands
| | | | | |
Collapse
|
29
|
Manzetti S, Zhang J, van der Spoel D. Thiamin Function, Metabolism, Uptake, and Transport. Biochemistry 2014; 53:821-35. [DOI: 10.1021/bi401618y] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Sergio Manzetti
- Uppsala
Center for Computational Chemistry, Science for Life Laboratory, Department
for Cell and Molecular Biology, University of Uppsala, Box 596, 751
24 Uppsala, Sweden
- Fjordforsk A.S., Fresvik 6896, Norway
| | - Jin Zhang
- Uppsala
Center for Computational Chemistry, Science for Life Laboratory, Department
for Cell and Molecular Biology, University of Uppsala, Box 596, 751
24 Uppsala, Sweden
- Department
of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - David van der Spoel
- Uppsala
Center for Computational Chemistry, Science for Life Laboratory, Department
for Cell and Molecular Biology, University of Uppsala, Box 596, 751
24 Uppsala, Sweden
| |
Collapse
|