1
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Daniel-Ivad PG, Van Lanen S, Ryan KS. Structure of the Oxygen, Pyridoxal Phosphate-Dependent Capuramycin Biosynthetic Protein Cap15. Biochemistry 2023; 62:2611-2621. [PMID: 37556254 DOI: 10.1021/acs.biochem.3c00216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Pyridoxal phosphate-dependent enzymes able to use oxygen as a co-substrate have emerged in multiple protein families. Here, we use crystallography to solve the 2.40 Å resolution crystal structure of Cap15, a nucleoside biosynthetic enzyme that catalyzes the oxidative decarboxylation of glycyl uridine. Our structural study captures the internal aldimine, pinpointing the active site lysine as K230 and showing the site of phosphate binding. Our docking studies reveal how Cap15 is able to catalyze a stereoselective deprotonation reaction, and bioinformatic analysis reveals active site residues that distinguish Cap15 from the structurally related d-glucosaminate-6-phosphate ammonia lyase and l-seryl-tRNA(Sec) selenium transferase (SelA). Our work provides the structural basis for further mechanistic investigation of a unique biosynthetic enzyme and provides a blueprint for understanding how oxygen reactivity emerged in the SelA-like protein family.
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Affiliation(s)
- Phillip G Daniel-Ivad
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Steven Van Lanen
- Pharmaceutical Sciences Department, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Katherine S Ryan
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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2
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Kurosawa S, Okamura H, Yoshida A, Tomita T, Sone Y, Hasebe F, Shinada T, Takikawa H, Kosono S, Nishiyama M. Mechanisms of Sugar Aminotransferase-like Enzymes to Synthesize Stereoisomers of Non-proteinogenic Amino Acids in Natural Product Biosynthesis. ACS Chem Biol 2023; 18:385-395. [PMID: 36669120 DOI: 10.1021/acschembio.2c00823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
(2,6)-Diamino-(5,7)-dihydroxyheptanoic acid (DADH), a non-proteinogenic amino acid, is converted to 1-azabicyclo[3.1.0]hexane ring-containing amino acids that are subsequently incorporated into ficellomycin and vazabitide A. The present study revealed that the sugar aminotransferase-like enzymes Fic25 and Vzb9, with a high amino acid sequence identity (56%) to each other, synthesized stereoisomers of DADH with (6S) and (6R) configurations, respectively. The crystal structure of the Fic25 complex with a PLP-(6S)-N2-acetyl-DADH adduct indicated that Asn45 and Gln197 (Asn205 and Ala53 in Vzb9) were located at positions that affected the stereochemistry of DADH being synthesized. A modeling study suggested that amino acid substitutions between Fic25 and Vzb9 allowed the enzymes to bind to the substrate with almost 180° rotation in the C5-C7 portions of the DADH molecules, accompanied by a concomitant shift in their C1-C4 portions. In support of this result, the replacement of two corresponding residues in Fic25 and Vzb9 increased (6R) and (6S) stereoselectivities, respectively. The different stereochemistry at C6 of DADH resulted in a different stereochemistry/orientation of the aziridine portion of the 1-azabicyclo[3.1.0]hexane ring, which plays a crucial role in biological activity, between ficellomycin and vazabitide A. A phylogenic analysis suggested that Fic25 and Vzb9 evolved from sugar aminotransferases to produce unusual building blocks for expanding the structural diversity of secondary metabolites.
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Affiliation(s)
- Sumire Kurosawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hironori Okamura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ayako Yoshida
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takeo Tomita
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yusuke Sone
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Fumihito Hasebe
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tetsuro Shinada
- Graduate School of Science, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka-shi, Osaka 558-8585, Japan
| | - Hirosato Takikawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Saori Kosono
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Makoto Nishiyama
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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3
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Chen M, Guo Z, Sun J, Tang W, Wang M, Tang Y, Li P, Wu B, Chen Y. Insights into the biosynthesis of septacidin l-heptosamine moiety unveils a VOC family sugar epimerase. Acta Pharm Sin B 2023; 13:765-774. [PMID: 36873169 PMCID: PMC9978623 DOI: 10.1016/j.apsb.2022.05.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/10/2022] [Accepted: 05/27/2022] [Indexed: 11/16/2022] Open
Abstract
l-Heptopyranoses are important components of bacterial polysaccharides and biological active secondary metabolites like septacidin (SEP), which represents a group of nucleoside antibiotics with antitumor, antifungal, and pain-relief activities. However, little is known about the formation mechanisms of those l-heptose moieties. In this study, we deciphered the biosynthetic pathway of the l,l-gluco-heptosamine moiety in SEPs by functional characterizing four genes and proposed that SepI initiates the process by oxidizing the 4'-hydroxyl of l-glycero-α-d-manno-heptose moiety of SEP-328 (2) to a keto group. Subsequently, SepJ (C5 epimerase) and SepA (C3 epimerase) shape the 4'-keto-l-heptopyranose moiety by sequential epimerization reactions. At the last step, an aminotransferase SepG installs the 4'-amino group of the l,l-gluco-heptosamine moiety to generate SEP-327 (3). An interesting phenomenon is that the SEP intermediates with 4'-keto-l-heptopyranose moieties exist as special bicyclic sugars with hemiacetal-hemiketal structures. Notably, l-pyranose is usually converted from d-pyranose by bifunctional C3/C5 epimerase. SepA is an unprecedented monofunctional l-pyranose C3 epimerase. Further in silico and experimental studies revealed that it represents an overlooked metal dependent-sugar epimerase family bearing vicinal oxygen chelate (VOC) architecture.
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Affiliation(s)
- Meng Chen
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhengyan Guo
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,Laboratory of Microbial Metabolic Engineering, Institute of Medicinal Biotechnology, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100050, China
| | - Jinyuan Sun
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Tang
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Wang
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China
| | - Yue Tang
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Pengwei Li
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bian Wu
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yihua Chen
- State Key Laboratory of Microbial Resources & CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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4
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Srivastava J, Balaji PV. Clues to reaction specificity in
PLP
‐dependent fold type I aminotransferases of monosaccharide biosynthesis. Proteins 2022; 90:1247-1258. [DOI: 10.1002/prot.26305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 01/20/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Jaya Srivastava
- Department of Biosciences and Bioengineering Indian Institute of Technology Bombay Mumbai India
| | - Petety V. Balaji
- Department of Biosciences and Bioengineering Indian Institute of Technology Bombay Mumbai India
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5
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Seltzner CA, Ferek JD, Thoden JB, Holden HM. Characterization of an aminotransferase from Acanthamoeba polyphaga Mimivirus. Protein Sci 2021; 30:1882-1894. [PMID: 34076307 DOI: 10.1002/pro.4139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 01/03/2023]
Abstract
Acanthamoeba polyphaga Mimivirus, a complex virus that infects amoeba, was first reported in 2003. It is now known that its DNA genome encodes for nearly 1,000 proteins including enzymes that are required for the biosynthesis of the unusual sugar 4-amino-4,6-dideoxy-d-glucose, also known as d-viosamine. As observed in some bacteria, the pathway for the production of this sugar initiates with a nucleotide-linked sugar, which in the Mimivirus is thought to be UDP-d-glucose. The enzyme required for the installment of the amino group at the C-4' position of the pyranosyl moiety is encoded in the Mimivirus by the L136 gene. Here, we describe a structural and functional analysis of this pyridoxal 5'-phosphate-dependent enzyme, referred to as L136. For this analysis, three high-resolution X-ray structures were determined: the wildtype enzyme/pyridoxamine 5'-phosphate/dTDP complex and the site-directed mutant variant K185A in the presence of either UDP-4-amino-4,6-dideoxy-d-glucose or dTDP-4-amino-4,6-dideoxy-d-glucose. Additionally, the kinetic parameters of the enzyme utilizing either UDP-d-glucose or dTDP-d-glucose were measured and demonstrated that L136 is efficient with both substrates. This is in sharp contrast to the structurally related DesI from Streptomyces venezuelae, whose three-dimensional architecture was previously reported by this laboratory. As determined in this investigation, DesI shows a profound preference in its catalytic efficiency for the dTDP-linked sugar substrate. This difference can be explained in part by a hydrophobic patch in DesI that is missing in L136. Notably, the structure of L136 reported here represents the first three-dimensional model for a virally encoded PLP-dependent enzyme and thus provides new information on sugar aminotransferases in general.
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Affiliation(s)
- Chase A Seltzner
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Justin D Ferek
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
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6
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Linehan MP, Thoden JB, Holden HM. Characterization of two enzymes from Psychrobacter cryohalolentis that are required for the biosynthesis of an unusual diacetamido-d-sugar. J Biol Chem 2021; 296:100463. [PMID: 33639157 PMCID: PMC8040287 DOI: 10.1016/j.jbc.2021.100463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 01/14/2023] Open
Abstract
Psychrobacter cryohalolentis strain K5T is a Gram-negative organism first isolated in 2006. It has a complex O-antigen that contains, in addition to l-rhamnose and d-galactose, two diacetamido- and a triacetamido-sugar. The biochemical pathways for the production of these unusual sugars are presently unknown. Utilizing the published genome sequence of the organism, we hypothesized that the genes 0612, 0638, and 0637 encode for a 4,6-dehydratase, an aminotransferase, and an N-acetyltransferase, respectively, which would be required for the biosynthesis of one of the diacetamido-sugars, 2,4-diacetamido-2,4,6-trideoxy-d-glucose, starting from UDP-N-acetylglucosamine. Here we present functional and structural data on the proteins encoded by the 0638 and 0637 genes. The kinetic properties of these enzymes were investigated by a discontinuous HPLC assay. An X-ray crystallographic structure of 0638, determined in its external aldimine form to 1.3 Å resolution, demonstrated the manner in which the UDP ligand is positioned into the active site. It is strikingly different from that previously observed for PglE from Campylobacter jejuni, which functions on the same substrate. Four X-ray crystallographic structures were also determined for 0637 in various complexed states at resolutions between 1.3 and 1.55 Å. Remarkably, a tetrahedral intermediate mimicking the presumed transition state was trapped in one of the complexes. The data presented herein confirm the hypothesized functions of these enzymes and provide new insight into an unusual sugar biosynthetic pathway in Gram-negative bacteria. We also describe an efficient method for acetyl-CoA synthesis that allowed us to overcome its prohibitive cost for this analysis.
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Affiliation(s)
- Michael P Linehan
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA.
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7
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Yan Y, Yang J, Wang L, Xu D, Yu Z, Guo X, Horsman GP, Lin S, Tao M, Huang SX. Biosynthetic access to the rare antiarose sugar via an unusual reductase-epimerase. Chem Sci 2020; 11:3959-3964. [PMID: 34122866 PMCID: PMC8152690 DOI: 10.1039/c9sc05766h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Rubrolones, isatropolones, and rubterolones are recently isolated glycosylated tropolonids with notable biological activity. They share similar aglycone skeletons but differ in their sugar moieties, and rubterolones in particular have a rare deoxysugar antiarose of unknown biosynthetic provenance. During our previously reported biosynthetic elucidation of the tropolone ring and pyridine moiety, gene inactivation experiments revealed that RubS3 is involved in sugar moiety biosynthesis. Here we report the in vitro characterization of RubS3 as a bifunctional reductase/epimerase catalyzing the formation of TDP-d-antiarose by epimerization at C3 and reduction at C4 of the key intermediate TDP-4-keto-6-deoxy-d-glucose. These new findings not only explain the biosynthetic pathway of deoxysugars in rubrolone-like natural products, but also introduce RubS3 as a new family of reductase/epimerase enzymes with potential to supply the rare antiarose unit for expanding the chemical space of glycosylated natural products. Rubrolones, isarubrolones, and rubterolones are recently isolated glycosylated tropolonids with notable biological activity.![]()
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Affiliation(s)
- Yijun Yan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
| | - Jing Yang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
| | - Li Wang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
| | - Dongdong Xu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
| | - Zhiyin Yu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
| | - Xiaowei Guo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
| | - Geoff P Horsman
- Department of Chemistry & Biochemistry, Wilfrid Laurier University Waterloo ON N2L 3C5 Canada
| | - Shuangjun Lin
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 China
| | - Meifeng Tao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 China
| | - Sheng-Xiong Huang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences Kunming 650201 China
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8
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Hofmeister DL, Thoden JB, Holden HM. Investigation of a sugar N-formyltransferase from the plant pathogen Pantoea ananatis. Protein Sci 2019; 28:707-716. [PMID: 30666752 PMCID: PMC6423709 DOI: 10.1002/pro.3577] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/13/2019] [Accepted: 01/14/2019] [Indexed: 02/05/2023]
Abstract
Pantoea ananatis is a Gram-negative bacterium first recognized in 1928 as the causative agent of pineapple rot in the Philippines. Since then various strains of the organism have been implicated in the devastation of agriculturally important crops. Some strains, however, have been shown to function as non-pathogenic plant growth promoting organisms. To date, the factors that determine pathogenicity or lack thereof between the various strains are not well understood. All P. ananatis strains contain lipopolysaccharides, which differ with respect to the identities of their associated sugars. Given our research interest on the presence of the unusual sugar, 4-formamido-4,6-dideoxy-d-glucose, found on the lipopolysaccharides of Campylobacter jejuni and Francisella tularensis, we were curious as to whether other bacteria have the appropriate biosynthetic machinery to produce these unique carbohydrates. Four enzymes are typically required for their biosynthesis: a thymidylyltransferase, a 4,6-dehydratase, an aminotransferase, and an N-formyltransferase. Here, we report that the gene SAMN03097714_1080 from the P. ananatis strain NFR11 does, indeed, encode for an N-formyltransferase, hereafter referred to as PA1080c. Our kinetic analysis demonstrates that PA1080c displays classical Michaelis-Menten kinetics with dTDP-4-amino-4,6-dideoxy-d-glucose as the substrate and N10 -formyltetrahydrofolate as the carbon source. In addition, the X-ray structure of PA1080c, determined to 1.7 Å resolution, shows that the enzyme adopts the molecular architecture observed for other sugar N-formyltransferases. Analysis of the P. ananatis NFR11 genome suggests that the three other enzymes necessary for N-formylated sugar biosynthesis are also present. Intriguingly, those strains of P. ananatis that are non-pathogenic apparently do not contain these genes.
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Affiliation(s)
| | - James B. Thoden
- Department of BiochemistryUniversity of WisconsinMadisonWisconsin, 53706
| | - Hazel M. Holden
- Department of BiochemistryUniversity of WisconsinMadisonWisconsin, 53706
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9
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Brown HA, Vinogradov E, Gilbert M, Holden HM. The Mycobacterium tuberculosis complex has a pathway for the biosynthesis of 4-formamido-4,6-dideoxy-d-glucose. Protein Sci 2018; 27:1491-1497. [PMID: 29761597 DOI: 10.1002/pro.3443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/10/2018] [Accepted: 05/10/2018] [Indexed: 11/08/2022]
Abstract
Recent studies have demonstrated that the O-antigens of some pathogenic bacteria such as Brucella abortus, Francisella tularensis, and Campylobacter jejuni contain quite unusual N-formylated sugars (3-formamido-3,6-dideoxy-d-glucose or 4-formamido-4,6-dideoxy-d-glucose). Typically, four enzymes are required for the formation of such sugars: a thymidylyltransferase, a 4,6-dehydratase, a pyridoxal 5'-phosphate or PLP-dependent aminotransferase, and an N-formyltransferase. To date, there have been no published reports of N-formylated sugars associated with Mycobacterium tuberculosis. A recent investigation from our laboratories, however, has demonstrated that one gene product from M. tuberculosis, Rv3404c, functions as a sugar N-formyltransferase. Given that M. tuberculosis produces l-rhamnose, both a thymidylyltransferase (Rv0334) and a 4,6-dehydratase (Rv3464) required for its formation have been identified. Thus, there is one remaining enzyme needed for the production of an N-formylated sugar in M. tuberculosis, namely a PLP-dependent aminotransferase. Here we demonstrate that the M. tuberculosis rv3402c gene encodes such an enzyme. Our data prove that M. tuberculosis contains all of the enzymatic activities required for the formation of dTDP-4-formamido-4,6-dideoxy-d-glucose. Indeed, the rv3402c gene product likely contributes to virulence or persistence during infection, though its temporal expression and location remain to be determined.
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Affiliation(s)
- Haley A Brown
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Evgeny Vinogradov
- Human Health Therapeutics, National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario, K1A OR6, Canada
| | - Michel Gilbert
- Human Health Therapeutics, National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario, K1A OR6, Canada
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
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10
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Uddin R, Rafi S. Structural and functional characterization of a unique hypothetical protein (WP_003901628.1) of Mycobacterium tuberculosis: a computational approach. Med Chem Res 2017. [DOI: 10.1007/s00044-017-1822-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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11
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Dow GT, Gilbert M, Thoden JB, Holden HM. Structural investigation on WlaRG from Campylobacter jejuni: A sugar aminotransferase. Protein Sci 2017; 26:586-599. [PMID: 28028852 DOI: 10.1002/pro.3109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 12/22/2016] [Indexed: 12/12/2022]
Abstract
Campylobacter jejuni is a Gram-negative bacterium that represents a leading cause of human gastroenteritis worldwide. Of particular concern is the link between C. jejuni infections and the subsequent development of Guillain-Barré syndrome, an acquired autoimmune disorder leading to paralysis. All Gram-negative bacteria contain complex glycoconjugates anchored to their outer membranes, but in most strains of C. jejuni, this lipoglycan lacks the O-antigen repeating units. Recent mass spectrometry analyses indicate that the C. jejuni 81116 (Penner serotype HS:6) lipoglycan contains two dideoxyhexosamine residues, and enzymological assay data show that this bacterial strain can synthesize both dTDP-3-acetamido-3,6-dideoxy-d-glucose and dTDP-3-acetamido-3,6-dideoxy-d-galactose. The focus of this investigation is on WlaRG from C. jejuni, which plays a key role in the production of these unusual sugars by functioning as a pyridoxal 5'-phosphate dependent aminotransferase. Here, we describe the first three-dimensional structures of the enzyme in various complexes determined to resolutions of 1.7 Å or higher. Of particular significance are the external aldimine structures of WlaRG solved in the presence of either dTDP-3-amino-3,6-dideoxy-d-galactose or dTDP-3-amino-3,6-dideoxy-d-glucose. These models highlight the manner in which WlaRG can accommodate sugars with differing stereochemistries about their C-4' carbon positions. In addition, we present a corrected structure of WbpE, a related sugar aminotransferase from Pseudomonas aeruginosa, solved to 1.3 Å resolution.
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Affiliation(s)
- Garrett T Dow
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Michel Gilbert
- National Research Council Canada, Human Health Therapeutics, Ottawa, Ontario, K1A 0R6, Canada
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
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12
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Jaing CJ, McLoughlin KS, Thissen JB, Zemla A, Gardner SN, Vergez LM, Bourguet F, Mabery S, Fofanov VY, Koshinsky H, Jackson PJ. Identification of Genome-Wide Mutations in Ciprofloxacin-Resistant F. tularensis LVS Using Whole Genome Tiling Arrays and Next Generation Sequencing. PLoS One 2016; 11:e0163458. [PMID: 27668749 PMCID: PMC5036845 DOI: 10.1371/journal.pone.0163458] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/08/2016] [Indexed: 11/19/2022] Open
Abstract
Francisella tularensis is classified as a Class A bioterrorism agent by the U.S. government due to its high virulence and the ease with which it can be spread as an aerosol. It is a facultative intracellular pathogen and the causative agent of tularemia. Ciprofloxacin (Cipro) is a broad spectrum antibiotic effective against Gram-positive and Gram-negative bacteria. Increased Cipro resistance in pathogenic microbes is of serious concern when considering options for medical treatment of bacterial infections. Identification of genes and loci that are associated with Ciprofloxacin resistance will help advance the understanding of resistance mechanisms and may, in the future, provide better treatment options for patients. It may also provide information for development of assays that can rapidly identify Cipro-resistant isolates of this pathogen. In this study, we selected a large number of F. tularensis live vaccine strain (LVS) isolates that survived in progressively higher Ciprofloxacin concentrations, screened the isolates using a whole genome F. tularensis LVS tiling microarray and Illumina sequencing, and identified both known and novel mutations associated with resistance. Genes containing mutations encode DNA gyrase subunit A, a hypothetical protein, an asparagine synthase, a sugar transamine/perosamine synthetase and others. Structural modeling performed on these proteins provides insights into the potential function of these proteins and how they might contribute to Cipro resistance mechanisms.
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Affiliation(s)
- Crystal J. Jaing
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
- * E-mail:
| | - Kevin S. McLoughlin
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - James B. Thissen
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Adam Zemla
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Shea N. Gardner
- Computations Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Lisa M. Vergez
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Feliza Bourguet
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | - Shalini Mabery
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
| | | | | | - Paul J. Jackson
- Physical Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, United States of America
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13
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Tang XL, Dai P, Gao H, Wang CX, Chen GD, Hong K, Hu D, Yao XS. A Single Gene Cluster for Chalcomycins and Aldgamycins: Genetic Basis for Bifurcation of Their Biosynthesis. Chembiochem 2016; 17:1241-9. [PMID: 27191535 DOI: 10.1002/cbic.201600118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Indexed: 01/27/2023]
Abstract
Aldgamycins are 16-membered macrolide antibiotics with a rare branched-chain sugar d-aldgarose or decarboxylated d-aldgarose at C-5. In our efforts to clone the gene cluster for aldgamycins from a marine-derived Streptomyces sp. HK-2006-1 capable of producing both aldgamycins and chalcomycins, we found that both are biosynthesized from a single gene cluster. Whole-genome sequencing combined with gene disruption established the entire gene cluster of aldgamycins: nine new genes are incorporated with the previously identified chalcomycin gene cluster. Functional analysis of these genes revealed that almDI/almDII, (encoding α/β subunits of pyruvate dehydrogenase) triggers the biosynthesis of aldgamycins, whereas almCI (encoding an oxidoreductase) initiates chalcomycins biosynthesis. This is the first report that aldgamycins and chalcomycins are derived from a single gene cluster and of the genetic basis for bifurcation in their biosynthesis.
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Affiliation(s)
- Xiao-Long Tang
- College of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, No. 103 Wenhua Road, Shenyang, 110016, China
| | - Ping Dai
- Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, No. 601 Huangpu Avenue, Guangzhou, 510632, China
| | - Hao Gao
- Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, No. 601 Huangpu Avenue, Guangzhou, 510632, China
| | - Chuan-Xi Wang
- Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, No. 601 Huangpu Avenue, Guangzhou, 510632, China
| | - Guo-Dong Chen
- Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, No. 601 Huangpu Avenue, Guangzhou, 510632, China
| | - Kui Hong
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, No. 185 Donghu Road, Wuhan, 430071, China
| | - Dan Hu
- Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, No. 601 Huangpu Avenue, Guangzhou, 510632, China.
| | - Xin-Sheng Yao
- College of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, No. 103 Wenhua Road, Shenyang, 110016, China. .,Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, No. 601 Huangpu Avenue, Guangzhou, 510632, China.
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14
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Zhu Y, Xu J, Mei X, Feng Z, Zhang L, Zhang Q, Zhang G, Zhu W, Liu J, Zhang C. Biochemical and Structural Insights into the Aminotransferase CrmG in Caerulomycin Biosynthesis. ACS Chem Biol 2016; 11:943-52. [PMID: 26714051 DOI: 10.1021/acschembio.5b00984] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Caerulomycin A (CRM A 1) belongs to a family of natural products containing a 2,2'-bipyridyl ring core structure and is currently under development as a potent novel immunosuppressive agent. Herein, we report the functional characterization, kinetic analysis, substrate specificity, and structure insights of an aminotransferase CrmG in 1 biosynthesis. The aminotransferase CrmG was confirmed to catalyze a key transamination reaction to convert an aldehyde group to an amino group in the 1 biosynthetic pathway, preferring l-glutamate and l-glutamine as the amino donor substrates. The crystal structures of CrmG in complex with the cofactor 5'-pyridoxal phosphate (PLP) or 5'-pyridoxamine phosphate (PMP) or the acceptor substrate were determined to adopt a canonical fold-type I of PLP-dependent enzymes with a unique small additional domain. The structure guided site-directed mutagenesis identified key amino acid residues for substrate binding and catalytic activities, thus providing insights into the transamination mechanism of CrmG.
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Affiliation(s)
- Yiguang Zhu
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Jinxin Xu
- Key
Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine
and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Xiangui Mei
- Key
Laboratory of Marine Drugs, Ministry of Education of China, School
of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Zhan Feng
- Key
Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine
and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Liping Zhang
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Qingbo Zhang
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Guangtao Zhang
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Weiming Zhu
- Key
Laboratory of Marine Drugs, Ministry of Education of China, School
of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Jinsong Liu
- Key
Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine
and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Changsheng Zhang
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
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15
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Cui L, Zhu Y, Guan X, Deng Z, Bai L, Feng Y. De Novo Biosynthesis of β-Valienamine in Engineered Streptomyces hygroscopicus 5008. ACS Synth Biol 2016; 5:15-20. [PMID: 26436873 DOI: 10.1021/acssynbio.5b00138] [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] [Indexed: 11/29/2022]
Abstract
The C7N aminocyclitol β-valienamine is a lead compound for the development of new biologically active β-glycosidase inhibitors as chemical chaperone therapeutic agents for lysosomal storage diseases. Its chemical synthesis is challenging due to the presence of multichiral centers in the structure. Herein, we took advantage of a heterogeneous aminotransferase with stereospecificity and designed a novel pathway for producing β-valienamine in Streptomyces hygroscopicus 5008, a validamycin producer. The aminotransferase BtrR from Bacillus circulans was able to convert valienone to β-valienamine with an optical purity of up to >99.9% enantiomeric excess value in vitro. When the aminotransferase gene was introduced into a mutant of S. hygroscopicus 5008 accumulating valienone, 20 mg/L of β-valienamine was produced after 96 h cultivation in shaking flasks. This work provides a powerful alternative for preparing the chiral intermediates for pharmaceutical development.
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Affiliation(s)
- Li Cui
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ying Zhu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaoqing Guan
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linquan Bai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yan Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
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16
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Wang F, Singh S, Xu W, Helmich KE, Miller MD, Cao H, Bingman CA, Thorson JS, Phillips GN. Structural Basis for the Stereochemical Control of Amine Installation in Nucleotide Sugar Aminotransferases. ACS Chem Biol 2015; 10:2048-56. [PMID: 26023720 DOI: 10.1021/acschembio.5b00244] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sugar aminotransferases (SATs) are an important class of tailoring enzymes that catalyze the 5'-pyridoxal phosphate (PLP)-dependent stereo- and regiospecific installation of an amino group from an amino acid donor (typically L-Glu or L-Gln) to a corresponding ketosugar nucleotide acceptor. Herein we report the strategic structural study of two homologous C4 SATs (Micromonospora echinospora CalS13 and Escherichia coli WecE) that utilize identical substrates but differ in their stereochemistry of aminotransfer. This study reveals for the first time a new mode of SAT sugar nucleotide binding and, in conjunction with previously reported SAT structural studies, provides the basis from which to propose a universal model for SAT stereo- and regiochemical control of amine installation. Specifically, the universal model put forth highlights catalytic divergence to derive solely from distinctions within nucleotide sugar orientation upon binding within a relatively fixed SAT active site where the available ligand bound structures of the three out of four representative C3 and C4 SAT examples provide a basis for the overall model. Importantly, this study presents a new predictive model to support SAT functional annotation, biochemical study and rational engineering.
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Affiliation(s)
| | - Shanteri Singh
- Center
for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, 789 South Limestone Street, Lexington, Kentucky 40536-0596, United States
| | | | - Kate E. Helmich
- Department
of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | | | | | - Craig A. Bingman
- Department
of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Jon S. Thorson
- Center
for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, 789 South Limestone Street, Lexington, Kentucky 40536-0596, United States
| | - George N. Phillips
- Department
of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
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17
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Riegert AS, Young NM, Watson DC, Thoden JB, Holden HM. Structure of the external aldimine form of PglE, an aminotransferase required for N,N'-diacetylbacillosamine biosynthesis. Protein Sci 2015; 24:1609-16. [PMID: 26178292 DOI: 10.1002/pro.2745] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/30/2015] [Indexed: 12/23/2022]
Abstract
N,N'-diacetylbacillosamine is a novel sugar that plays a key role in bacterial glycosylation. Three enzymes are required for its biosynthesis in Campylobacter jejuni starting from UDP-GlcNAc. The focus of this investigation, PglE, catalyzes the second step in the pathway. It is a PLP-dependent aminotransferase that converts UDP-2-acetamido-4-keto-2,4,6-trideoxy-d-glucose to UDP-2-acetamido-4-amino-2,4,6-trideoxy-d-glucose. For this investigation, the structure of PglE in complex with an external aldimine was determined to a nominal resolution of 2.0 Å. A comparison of its structure with those of other sugar aminotransferases reveals a remarkable difference in the manner by which PglE accommodates its nucleotide-linked sugar substrate.
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Affiliation(s)
- Alexander S Riegert
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - N Martin Young
- Human Health Therapeutics, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - David C Watson
- Human Health Therapeutics, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
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18
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Singh S, Kim Y, Wang F, Bigelow L, Endres M, Kharel MK, Babnigg G, Bingman CA, Joachimiak A, Thorson JS, Phillips GN. Structural characterization of AtmS13, a putative sugar aminotransferase involved in indolocarbazole AT2433 aminopentose biosynthesis. Proteins 2015; 83:1547-54. [PMID: 26061967 DOI: 10.1002/prot.24844] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/25/2015] [Accepted: 05/27/2015] [Indexed: 11/08/2022]
Abstract
AT2433 from Actinomadura melliaura is an indolocarbazole antitumor antibiotic structurally distinguished by its unique aminodideoxypentose-containing disaccharide moiety. The corresponding sugar nucleotide-based biosynthetic pathway for this unusual sugar derives from comparative genomics where AtmS13 has been suggested as the contributing sugar aminotransferase (SAT). Determination of the AtmS13 X-ray structure at 1.50-Å resolution reveals it as a member of the aspartate aminotransferase fold type I (AAT-I). Structural comparisons of AtmS13 with homologous SATs that act upon similar substrates implicate potential active site residues that contribute to distinctions in sugar C5 (hexose vs. pentose) and/or sugar C2 (deoxy vs. hydroxyl) substrate specificity.
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Affiliation(s)
- Shanteri Singh
- Center for Pharmaceutical Research and Innovation, Pharmaceutical Sciences Division, University of Kentucky College of Pharmacy, Lexington, Kentucky, 40536-0596
| | - Youngchang Kim
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, 60439
| | - Fengbin Wang
- Department of BioSciences, Rice University, Houston, Texas, 77005
| | - Lance Bigelow
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, 60439
| | - Michael Endres
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, 60439
| | - Madan K Kharel
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Maryland Eastern Shore, Princess Anne, Maryland
| | - Gyorgy Babnigg
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, 60439
| | - Craig A Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, 60439
| | - Jon S Thorson
- Center for Pharmaceutical Research and Innovation, Pharmaceutical Sciences Division, University of Kentucky College of Pharmacy, Lexington, Kentucky, 40536-0596
| | - George N Phillips
- Department of BioSciences, Rice University, Houston, Texas, 77005.,Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706.,Department of Chemistry, Rice University, Houston, Texas, 77005
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19
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Zimmer AL, Thoden JB, Holden HM. Three-dimensional structure of a sugar N-formyltransferase from Francisella tularensis. Protein Sci 2014; 23:273-83. [PMID: 24347283 DOI: 10.1002/pro.2409] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/06/2013] [Accepted: 12/11/2013] [Indexed: 11/08/2022]
Abstract
N-formylated sugars have been observed on the O-antigens of such pathogenic Gram-negative bacteria as Campylobacter jejuni and Francisella tularensis. Until recently, however, little was known regarding the overall molecular architectures of the N-formyltransferases that are required for the biosynthesis of these unusual sugars. Here we demonstrate that the protein encoded by the wbtj gene from F. tularensis is an N-formyltransferase that functions on dTDP-4-amino-4,6-dideoxy-d-glucose as its substrate. The enzyme, hereafter referred to as WbtJ, demonstrates a strict requirement for N(10) -formyltetrahydrofolate as its carbon source. In addition to the kinetic analysis, the three-dimensional structure of the enzyme was solved in the presence of dTDP-sugar ligands to a nominal resolution of 2.1 Å. Each subunit of the dimeric enzyme is dominated by a "core" domain defined by Met 1 to Ser 185. This core motif harbors the active site residues. Following the core domain, the last 56 residues fold into two α-helices and a β-hairpin motif. The hairpin motif is responsible primarily for the subunit:subunit interface, which is characterized by a rather hydrophobic pocket. From the study presented here, it is now known that WbtJ functions on C-4' amino sugars. Another enzyme recently investigated in the laboratory, WlaRD, formylates only C-3' amino sugars. Strikingly, the quaternary structures of WbtJ and WlaRD are remarkably different. In addition, there are several significant variations in the side chains that line their active site pockets, which may be important for substrate specificity. Details concerning the kinetic and structural properties of WbtJ are presented.
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Affiliation(s)
- Alex L Zimmer
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
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20
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Morrison MJ, Imperiali B. The renaissance of bacillosamine and its derivatives: pathway characterization and implications in pathogenicity. Biochemistry 2014; 53:624-38. [PMID: 24383882 PMCID: PMC3951908 DOI: 10.1021/bi401546r] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Prokaryote-specific
sugars, including N,N′-diacetylbacillosamine
(diNAcBac) and pseudaminic
acid, have experienced a renaissance in the past decade because of
their discovery in glycans related to microbial pathogenicity. DiNAcBac
is found at the reducing end of oligosaccharides of N- and O-linked
bacterial protein glycosylation pathways of Gram-negative pathogens,
including Campylobacter jejuni and Neisseria
gonorrhoeae. Further derivatization of diNAcBac results in
the nonulosonic acid known as legionaminic acid, which was first characterized
in the O-antigen of the lipopolysaccharide (LPS) in Legionella
pneumophila. Pseudaminic acid, an isomer of legionaminic
acid, is also important in pathogenic bacteria such as Helicobacter
pylori because of its occurrence in O-linked glycosylation
of flagellin proteins, which plays an important role in flagellar
assembly and motility. Here, we present recent advances in the characterization
of the biosynthetic pathways leading to these highly modified sugars
and investigation of the roles that each plays in bacterial fitness
and pathogenicity.
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Affiliation(s)
- Michael J Morrison
- Departments of Chemistry and Biology, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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21
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Metsä-Ketelä M, Oja T, Taguchi T, Okamoto S, Ichinose K. Biosynthesis of pyranonaphthoquinone polyketides reveals diverse strategies for enzymatic carbon–carbon bond formation. Curr Opin Chem Biol 2013; 17:562-70. [DOI: 10.1016/j.cbpa.2013.06.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/30/2013] [Accepted: 06/25/2013] [Indexed: 11/26/2022]
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22
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Singh S, Phillips GN, Thorson JS. The structural biology of enzymes involved in natural product glycosylation. Nat Prod Rep 2012; 29:1201-37. [PMID: 22688446 DOI: 10.1039/c2np20039b] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The glycosylation of microbial natural products often dramatically influences the biological and/or pharmacological activities of the parental metabolite. Over the past decade, crystal structures of several enzymes involved in the biosynthesis and attachment of novel sugars found appended to natural products have emerged. In many cases, these studies have paved the way to a better understanding of the corresponding enzyme mechanism of action and have served as a starting point for engineering variant enzymes to facilitate to production of differentially-glycosylated natural products. This review specifically summarizes the structural studies of bacterial enzymes involved in biosynthesis of novel sugar nucleotides.
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Affiliation(s)
- Shanteri Singh
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
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23
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Piacente F, Marin M, Molinaro A, De Castro C, Seltzer V, Salis A, Damonte G, Bernardi C, Claverie JM, Abergel C, Tonetti M. Giant DNA virus mimivirus encodes pathway for biosynthesis of unusual sugar 4-amino-4,6-dideoxy-D-glucose (Viosamine). J Biol Chem 2012; 287:3009-18. [PMID: 22157758 PMCID: PMC3270958 DOI: 10.1074/jbc.m111.314559] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mimivirus is one the largest DNA virus identified so far, infecting several Acanthamoeba species. Analysis of its genome revealed the presence of a nine-gene cluster containing genes potentially involved in glycan formation. All of these genes are co-expressed at late stages of infection, suggesting their role in the formation of the long fibers covering the viral surface. Among them, we identified the L136 gene as a pyridoxal phosphate-dependent sugar aminotransferase. This enzyme was shown to catalyze the formation of UDP-4-amino-4,6-dideoxy-D-glucose (UDP-viosamine) from UDP-4-keto-6-deoxy-D-glucose, a key compound involved also in the biosynthesis of L-rhamnose. This finding further supports the hypothesis that Mimivirus encodes a glycosylation system that is completely independent of the amoebal host. Viosamine, together with rhamnose, (N-acetyl)glucosamine, and glucose, was found as a major component of the viral glycans. Most of the sugars were associated with the fibers, confirming a capsular-like nature of the viral surface. Phylogenetic analysis clearly indicated that L136 was not a recent acquisition from bacteria through horizontal gene transfer, but it was acquired very early during evolution. Implications for the origin of the glycosylation machinery in giant DNA virus are also discussed.
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Affiliation(s)
- Francesco Piacente
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV/1, 16132 Genova, Italy
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24
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Kubiak RL, Holden HM. Structural studies of AntD: an N-Acyltransferase involved in the biosynthesis of D-Anthrose. Biochemistry 2012; 51:867-78. [PMID: 22220494 DOI: 10.1021/bi201650c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The unusual dideoxy sugar d-anthrose has been identified as an important component in the endospores of infectious agents such as Bacillus anthracis and Bacillus cereus. Specifically, it is the terminal sugar on the bacterium's exosporium, and it provides a point of interaction between the spore and the host. The biosynthesis of d-anthrose involves numerous steps starting from α-d-glucose 1-phosphate. Here we present a combined structural and functional investigation of AntD from B. cereus. This enzyme plays a key role in d-anthrose biosynthesis by catalyzing the acylation of the C-4″ amino group of dTDP-4-amino-4,6-dideoxyglucose using 3-hydroxy-3-methylbutyryl-CoA as the acyl donor. For this investigation, two ternary complexes of AntD were determined to 1.8 Å resolution: one in which the protein contained bound β-hydroxybutyryl-CoA and dTDP and the second with CoA and dTDP-4-amino-4,6-dideoxyglucose. On the basis of these high-resolution structures, it was shown that the side chain of Asp 94 lies within hydrogen bonding distance of the sugar C-4″ amino group, and the side chain of Ser 84 resides near the carbonyl oxygen of β-hydroxybutyryl-CoA. To test the roles of these residues in the catalytic mechanism of AntD, various site-directed mutant proteins were prepared and subjected to kinetic and structural analyses. The D94A and D94N mutant proteins demonstrated enzymatic activity, albeit with significantly reduced catalytic efficiencies. The S84A mutant protein showed an approximate 10-fold decrease in activity. Interestingly, the S84C and S84T mutant proteins were both active but demonstrated substrate inhibition. The three-dimensional structures of all of the mutant proteins were nearly identical to that of the wild-type enzyme, indicating that the changes in their kinetic parameters were not due to major conformational changes. Taken together, these data suggest that Asp 94 is important for substrate binding, but probably does not function as an enzymatic base, and that Ser 84 most likely plays a role in the formation of an oxyanion hole.
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Affiliation(s)
- Rachel L Kubiak
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
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25
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Romo AJ, Liu HW. Mechanisms and structures of vitamin B(6)-dependent enzymes involved in deoxy sugar biosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1814:1534-47. [PMID: 21315852 PMCID: PMC3115481 DOI: 10.1016/j.bbapap.2011.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 01/08/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
Abstract
PLP is well-regarded for its role as a coenzyme in a number of diverse enzymatic reactions. Transamination, deoxygenation, and aldol reactions mediated by PLP-dependent enzymes enliven and enrich deoxy sugar biosynthesis, endowing these compounds with unique structures and contributing to their roles as determinants of biological activity in many natural products. The importance of deoxy aminosugars in natural product biosynthesis has spurred several recent structural investigations of sugar aminotransferases. The structure of a PMP-dependent enzyme catalyzing the C-3 deoxygenation reaction in the biosynthesis of ascarylose was also determined. These studies, and the crystal structures they have provided, offer a wealth of new insights regarding the enzymology of PLP/PMP-dependent enzymes in deoxy sugar biosynthesis. In this review, we consider these recent achievements in the structural biology of deoxy sugar biosynthetic enzymes and the important implications they hold for understanding enzyme catalysis and natural product biosynthesis in general. This article is part of a Special Issue entitled: Pyridoxal Phosphate Enzymology.
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Affiliation(s)
- Anthony J. Romo
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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Larkin A, Olivier NB, Imperiali B. Structural analysis of WbpE from Pseudomonas aeruginosa PAO1: a nucleotide sugar aminotransferase involved in O-antigen assembly. Biochemistry 2010; 49:7227-37. [PMID: 20604544 DOI: 10.1021/bi100805b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In recent years, the opportunistic pathogen Pseudomonas aeruginosa has emerged as a major source of hospital-acquired infections. Effective treatment has proven increasingly difficult due to the spread of multidrug resistant strains and thus requires a deeper understanding of the biochemical mechanisms of pathogenicity. The central carbohydrate of the P. aeruginosa PAO1 (O5) B-band O-antigen, ManNAc(3NAc)A, has been shown to be critical for virulence and is produced in a stepwise manner by five enzymes in the Wbp pathway (WbpA, WbpB, WbpE, WbpD, and WbpI). Herein, we present the crystal structure of the aminotransferase WbpE from P. aeruginosa PAO1 in complex with the cofactor pyridoxal 5'-phosphate (PLP) and product UDP-GlcNAc(3NH(2))A as the external aldimine at 1.9 A resolution. We also report the structures of WbpE in complex with PMP alone as well as the PLP internal aldimine and show that the dimeric structure of WbpE observed in the crystal structure is confirmed by analytical ultracentrifugation. Analysis of these structures reveals that the active site of the enzyme is composed of residues from both subunits. In particular, we show that a key residue (Arg229), which has previously been implicated in direct interactions with the alpha-carboxylate moiety of alpha-ketoglutarate, is also uniquely positioned to bestow specificity for the 6''-carboxyl group of GlcNAc(3NH(2))A through a salt bridge. This finding is intriguing because while an analogous basic residue is present in WbpE homologues that do not process 6''-carboxyl-modified saccharides, recent structural studies reveal that this side chain is retracted to accommodate a neutral C6'' atom. This work represents the first structural analysis of a nucleotide sugar aminotransferase with a bound product modified at the C2'', C3'', and C6'' positions and provides insight into a novel target for treatment of P. aeruginosa infection.
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Affiliation(s)
- Angelyn Larkin
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Holden HM, Cook PD, Thoden JB. Biosynthetic enzymes of unusual microbial sugars. Curr Opin Struct Biol 2010; 20:543-50. [PMID: 20832292 DOI: 10.1016/j.sbi.2010.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 05/07/2010] [Accepted: 08/11/2010] [Indexed: 11/18/2022]
Abstract
The biological importance of proteins and nucleic acids in the natural world is undeniable, and research efforts on these macromolecules have often overshadowed those directed at carbohydrates. It is now known, however, that carbohydrates not only play roles in energy storage and plant cell wall structure, but are also intimately involved in such processes as fertilization, the immune response, and cell adhesion. Indeed, recent years have seen an explosion in research efforts directed at uncovering and understanding new sugar moieties. The dideoxysugars and trideoxysugars, which are synthesized by a variety of bacteria, fungi, and plants, represent an especially intriguing class of carbohydrates. They are found, for example, on the lipopolysaccharides of some Gram-negative bacteria or on antibacterial agents such as erythromycin. Many of them are formed from simple monosaccharides such as glucose-6-phosphate or fructose-6-phosphate via a myriad of enzymatic reactions including acetylations, aminations, dehydrations, epimerizations, reductions, and methylations. In this review we focus on the recent structural investigations of the bacterial N-acetyltransferases and the PLP-dependent aminotransferases that function on nucleotide-linked sugar substrates.
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Affiliation(s)
- Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA.
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Pageni BB, Oh TJ, Sohng JK. Novel desosaminyl derivatives of dihydrochalcomycin from a genetically engineered strain of Streptomyces sp. Biotechnol Lett 2009; 31:1759-68. [PMID: 19590827 DOI: 10.1007/s10529-009-0074-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 06/16/2009] [Accepted: 06/19/2009] [Indexed: 11/30/2022]
Abstract
Dihydrochalcomycin from Streptomyces sp. KCTC 0041BP is a 16-membered macrolide antibiotic containing two deoxysugars (D-chalcose and D-mycinose) that are O-glycosylated at the C-5 and C-20 positions, respectively. The desosamine sugar cassette was constructed from pikromycin-deoxysugar biosynthetic genes and transformed into Streptomyces sp. GerSM1, which was engineered for deletion of the genes related to TDP-D-chalcose biosynthesis (gerB, gerN and gerMI). Novel 16-membered macrolides (5-O-desosaminyl derivatives of dihydrochalcomycin) were detected by ESI-MS, LC/MS, and MS/MS thereby demonstrating combinatorial biosynthesis of the deoxysugar in 16-membered macrolide antibiotics.
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Affiliation(s)
- Binod Babu Pageni
- Institute of Biomolecule Reconstruction, Department of Pharmaceutical Engineering, SunMoon University, #100, Kalsan-ri, Tangjeong-myeon, Asansi, Chungnam, 336-708, Korea
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29
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Thoden JB, Schäffer C, Messner P, Holden HM. Structural analysis of QdtB, an aminotransferase required for the biosynthesis of dTDP-3-acetamido-3,6-dideoxy-alpha-D-glucose. Biochemistry 2009; 48:1553-61. [PMID: 19178182 DOI: 10.1021/bi8022015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
3-Acetamido-3,6-dideoxy-alpha-d-glucose or Quip3NAc is an unusual deoxyamino sugar found in the O-antigens of some Gram-negative bacteria and in the S-layers of Gram-positive bacteria. It is synthesized in these organisms as a dTDP-linked sugar via the action of five enzymes. The focus of this investigation is on QdtB from Thermoanaerobacterium thermosaccharolyticum E207-71, a PLP-dependent aminotransferase that catalyzes the penultimate step in the production of dTDP-Quip3NAc. For this analysis, the enzyme was crystallized in the presence of its product, dTDP-Quip3N, and the structure was solved and refined to 2.15 A resolution. QdtB is a dimer, and its overall fold places it into the well-characterized aspartate aminotransferase superfamily. Electron density corresponding to the bound product reveals the presence of a Schiff base between C-4' of the PLP cofactor and the amino nitrogen of the sugar. Those amino acid side chains involved in binding the dTDP-sugar into the active site include Tyr 183, His 309, and Tyr 310 from subunit 1 and Lys 219 from subunit 2. Notably there is a decided lack of interactions between the pyranosyl C-4' hydroxyl of the dTDP-sugar and the protein. In keeping with this observation, we show that QdtB can also turn over dTDP-3-acetamido-3,6-dideoxy-alpha-d-galactose. This investigation represents the first structural analysis of a sugar-modifying aminotransferase with a bound product in its active site that functions at the C-3' rather than the C-4' position of the hexose.
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Affiliation(s)
- James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
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Thibodeaux C, Melançon C, Liu HW. Biosynthese von Naturstoffzuckern und enzymatische Glycodiversifizierung. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801204] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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31
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Timmons SC, Thorson JS. Increasing carbohydrate diversity via amine oxidation: aminosugar, hydroxyaminosugar, nitrososugar, and nitrosugar biosynthesis in bacteria. Curr Opin Chem Biol 2008; 12:297-305. [PMID: 18424273 PMCID: PMC2517148 DOI: 10.1016/j.cbpa.2008.03.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 03/19/2008] [Accepted: 03/19/2008] [Indexed: 12/14/2022]
Abstract
Bacterial secondary metabolites often contain carbohydrate attachments that play a significant role in conferring biological activity. A small proportion of these bioactive sugars are derived from aminosugar oxidation to ultimately provide hydroxyaminosugars, nitrososugars, and nitrosugars. Recent advances in the elucidation of hydroxyaminosugar-, nitrososugar-, and nitrosugar-containing natural product gene clusters have enabled the proposal of biosynthetic pathways, the in vitro characterization of aminosugar oxidases, and the structure determination of key enzymes. This article focuses upon the key enzymatic transformations in aminosugar, hydroxyaminosugar, nitrososugar, and nitrosugar biosynthesis, as well as the unique chemical reactivity of alkoxyaminosugars, with a particular focus upon developments within the past two years.
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Affiliation(s)
- Shannon C. Timmons
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705; University of Wisconsin National Cooperative Drug Discovery Group Program
| | - Jon S. Thorson
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705; University of Wisconsin National Cooperative Drug Discovery Group Program
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Thibodeaux CJ, Melançon CE, Liu HW. Natural-product sugar biosynthesis and enzymatic glycodiversification. Angew Chem Int Ed Engl 2008; 47:9814-59. [PMID: 19058170 PMCID: PMC2796923 DOI: 10.1002/anie.200801204] [Citation(s) in RCA: 315] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many biologically active small-molecule natural products produced by microorganisms derive their activities from sugar substituents. Changing the structures of these sugars can have a profound impact on the biological properties of the parent compounds. This realization has inspired attempts to derivatize the sugar moieties of these natural products through exploitation of the sugar biosynthetic machinery. This approach requires an understanding of the biosynthetic pathway of each target sugar and detailed mechanistic knowledge of the key enzymes. Scientists have begun to unravel the biosynthetic logic behind the assembly of many glycosylated natural products and have found that a core set of enzyme activities is mixed and matched to synthesize the diverse sugar structures observed in nature. Remarkably, many of these sugar biosynthetic enzymes and glycosyltransferases also exhibit relaxed substrate specificity. The promiscuity of these enzymes has prompted efforts to modify the sugar structures and alter the glycosylation patterns of natural products through metabolic pathway engineering and enzymatic glycodiversification. In applied biomedical research, these studies will enable the development of new glycosylation tools and generate novel glycoforms of secondary metabolites with useful biological activity.
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Affiliation(s)
- Christopher J. Thibodeaux
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
| | - Charles E. Melançon
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
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Thibodeaux CJ, Melançon CE, Liu HW. Natural-product sugar biosynthesis and enzymatic glycodiversification. Angew Chem Int Ed Engl 2008. [PMID: 19058170 DOI: 10.1002/anie] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Many biologically active small-molecule natural products produced by microorganisms derive their activities from sugar substituents. Changing the structures of these sugars can have a profound impact on the biological properties of the parent compounds. This realization has inspired attempts to derivatize the sugar moieties of these natural products through exploitation of the sugar biosynthetic machinery. This approach requires an understanding of the biosynthetic pathway of each target sugar and detailed mechanistic knowledge of the key enzymes. Scientists have begun to unravel the biosynthetic logic behind the assembly of many glycosylated natural products and have found that a core set of enzyme activities is mixed and matched to synthesize the diverse sugar structures observed in nature. Remarkably, many of these sugar biosynthetic enzymes and glycosyltransferases also exhibit relaxed substrate specificity. The promiscuity of these enzymes has prompted efforts to modify the sugar structures and alter the glycosylation patterns of natural products through metabolic pathway engineering and enzymatic glycodiversification. In applied biomedical research, these studies will enable the development of new glycosylation tools and generate novel glycoforms of secondary metabolites with useful biological activity.
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Affiliation(s)
- Christopher J Thibodeaux
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX 78712, USA
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34
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Cook PD, Holden HM. GDP-4-keto-6-deoxy-D-mannose 3-dehydratase, accommodating a sugar substrate in the active site. J Biol Chem 2007; 283:4295-303. [PMID: 18045869 DOI: 10.1074/jbc.m708893200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Colitose is a dideoxysugar found in the O-antigen of the lipopolysaccharide that coats the outer membrane of some Gram-negative bacteria. Four enzymes are required for its production starting from D-mannose-1-phosphate and GTP. The focus of this investigation is GDP-4-keto-6-deoxy-D-mannose 3-dehydratase or ColD, which catalyzes the removal of the C3'-hydroxyl group from GDP-4-keto-6-deoxymannose. The enzyme is pyridoxal 5'-phosphate-dependent, but unlike most of these proteins, the conserved lysine residue that covalently holds the cofactor in the active site is replaced with a histidine residue. Here we describe the three-dimensional structure of ColD, determined to 1.7A resolution, whereby the active site histidine has been replaced with an asparagine residue. For this investigation, crystals of the site-directed mutant protein were grown in the presence of GDP-4-amino-4,6-dideoxy-D-mannose (GDP-perosamine). The electron density map clearly reveals the presence of the sugar analog trapped in the active site as an external aldimine. The active site is positioned between the two subunits of the dimer. Whereas the pyrophosphoryl groups of the ligand are anchored to the protein via Arg-219 and Arg-331, the hydroxyl groups of the hexose only lie within hydrogen bonding distance to ordered water molecules. Interestingly, the hexose moiety of the ligand adopts a boat rather than the typically observed chair conformation. Activity assays demonstrate that this mutant protein cannot catalyze the dehydration step. Additionally, we report data revealing that wild-type ColD is able to catalyze the production of GDP-4-keto-3,6-dideoxymannose using GDP-perosamine instead of GDP-4-keto-6-deoxymannose as a substrate.
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Affiliation(s)
- Paul D Cook
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706-1544, USA
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