1
|
Cui FJ, Fu X, Sun L, Zan XY, Meng LJ, Sun WJ. Recent insights into glucans biosynthesis and engineering strategies in edible fungi. Crit Rev Biotechnol 2023:1-18. [PMID: 38105513 DOI: 10.1080/07388551.2023.2289341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 04/21/2023] [Indexed: 12/19/2023]
Abstract
Fungal α/β-glucans have significant importance in cellular functions including cell wall structure, host-pathogen interactions and energy storage, and wide application in high-profile fields, including food, nutrition, and pharmaceuticals. Fungal species and their growth/developmental stages result in a diversity of glucan contents, structures and bioactivities. Substantial progresses have been made to elucidate the fine structures and functions, and reveal the potential molecular synthesis pathway of fungal α/β-glucans. Herein, we review the current knowledge about the biosynthetic machineries, including: precursor UDP-glucose synthesis, initiation, elongation/termination and remodeling of α/β-glucan chains, and molecular regulation to maximally produce glucans in edible fungi. This review would provide future perspectives to biosynthesize the targeted glucans and reveal the catalytic mechanism of enzymes associated with glucan synthesis, including: UDP-glucose pyrophosphate phosphorylases (UGP), glucan synthases, and glucanosyltransferases in edible fungi.
Collapse
Affiliation(s)
- Feng-Jie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-production, Dexing, P. R. China
| | - Xin Fu
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Lei Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Xin-Yi Zan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Li-Juan Meng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Wen-Jing Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-production, Dexing, P. R. China
| |
Collapse
|
2
|
Du X, Chu X, Liu N, Jia X, Peng H, Xiao Y, Liu L, Yu H, Li F, He C. Structures of the NDP-pyranose mutase belonging to glycosyltransferase family 75 reveal residues important for Mn 2+ coordination and substrate binding. J Biol Chem 2023; 299:102903. [PMID: 36642179 PMCID: PMC9937993 DOI: 10.1016/j.jbc.2023.102903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/29/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Members of glycosyltransferase family 75 (GT75) not only reversibly catalyze the autoglycosylation of a conserved arginine residue with specific NDP-sugars but also exhibit NDP-pyranose mutase activity that reversibly converts specific NDP-pyranose to NDP-furanose. The latter activity provides valuable NDP-furanosyl donors for glycosyltransferases and requires a divalent cation as a cofactor instead of FAD used by UDP-D-galactopyranose mutase. However, details of the mechanism for NDP-pyranose mutase activity are not clear. Here we report the first crystal structures of GT75 family NDP-pyranose mutases. The novel structures of GT75 member MtdL in complex with Mn2+ and GDP, GDP-D-glucopyranose, GDP-L-fucopyranose, GDP-L-fucofuranose, respectively, combined with site-directed mutagenesis studies, reveal key residues involved in Mn2+ coordination, substrate binding, and catalytic reactions. We also provide a possible catalytic mechanism for this unique type of NDP-pyranose mutase. Taken together, our results highlight key elements of an enzyme family important for furanose biosynthesis.
Collapse
Affiliation(s)
- Xueqing Du
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Xuan Chu
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Ning Liu
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Xiaoyu Jia
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Hui Peng
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Yazhong Xiao
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Lin Liu
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China
| | - Haizhu Yu
- Department of Chemistry and Centre for Atomic Engineering of Advanced Materials, Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University, Hefei, China
| | - Fudong Li
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Chao He
- Anhui Key Laboratory of Modern Biomanufacturing and School of Life Sciences, Anhui University, Hefei, Anhui, China.
| |
Collapse
|
3
|
Verhertbruggen Y, Bouder A, Vigouroux J, Alvarado C, Geairon A, Guillon F, Wilkinson MD, Stritt F, Pauly M, Lee MY, Mortimer JC, Scheller HV, Mitchell RAC, Voiniciuc C, Saulnier L, Chateigner-Boutin AL. The TaCslA12 gene expressed in the wheat grain endosperm synthesizes wheat-like mannan when expressed in yeast and Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 302:110693. [PMID: 33288007 DOI: 10.1016/j.plantsci.2020.110693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/24/2020] [Accepted: 09/26/2020] [Indexed: 06/12/2023]
Abstract
Mannan is a class of cell wall polysaccharides widespread in the plant kingdom. Mannan structure and properties vary according to species and organ. The cell walls of cereal grains have been extensively studied due to their role in cereal processing and to their beneficial effect on human health as dietary fiber. Recently, we showed that mannan in wheat (Triticum aestivum) grain endosperm has a linear structure of β-1,4-linked mannose residues. The aim of this work was to study the biosynthesis and function of wheat grain mannan. We showed that mannan is deposited in the endosperm early during grain development, and we identified candidate mannan biosynthetic genes expressed in the endosperm. The functional study in wheat was unsuccessful therefore our best candidate genes were expressed in heterologous systems. The endosperm-specificTaCslA12 gene expressed in Pichia pastoris and in an Arabidopsis thaliana mutant depleted in glucomannan led to the production of wheat-like linear mannan lacking glucose residues and with moderate acetylation. Therefore, this gene encodes a mannan synthase and is likely responsible for the synthesis of wheat endosperm mannan.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Mark D Wilkinson
- Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JK, UK
| | - Fabian Stritt
- Institute for Plant Cell Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Markus Pauly
- Institute for Plant Cell Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Mi Yeon Lee
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jenny C Mortimer
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Henrik V Scheller
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | | | - Cătălin Voiniciuc
- Institute for Plant Cell Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; Independent Junior Research Group-Designer Glycans, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany
| | | | | |
Collapse
|
4
|
Surana P, Jainarayanan AK, Anand NM, Sharma M. Analysing non-synonymous mutations in XDR and MDR tuberculosis drugs. J Clin Tuberc Other Mycobact Dis 2019; 17:100124. [PMID: 31788566 PMCID: PMC6880092 DOI: 10.1016/j.jctube.2019.100124] [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] [Indexed: 11/20/2022] Open
Abstract
Tuberculosis is a bacterial disease caused by Mycobacterium tuberculosis. It is known to be the second-largest cause of death and models a severe risk to public health throughout the world. Though it affects people of almost every age, individuals with weakened immune systems, (e.g., HIV infection) are more likely to get infected. The present study deals with analyzing non-synonymous mutations in anti-tuberculosis drugs, which may have a significant role in causing XDR and MDR tuberculosis drug resistance. Continued use of tuberculosis drugs, discontinuation of medicines and various other factors can promote drug resistance in the host's body. To understand the actual cause of resistance, we have identified some patterns of mutations which might be responsible for a change in the structure of the protein, ultimately causing drug resistance. Here, we aim to present some of the unique mutation patterns in the genes associated with the marketed drugs that might have a deleterious effect. In this study, we have used molecular docking approach for understanding the ligand binding affinity of the mutated drugs. The results are further validated by molecular dynamics studies.
Collapse
Affiliation(s)
| | - Ashwin Kumar Jainarayanan
- Indian Institute of Science Education and Research, Mohali, India
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Mukta Sharma
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| |
Collapse
|
5
|
Albesa-Jové D, Cifuente JO, Trastoy B, Guerin ME. Quick-soaking of crystals reveals unprecedented insights into the catalytic mechanism of glycosyltransferases. Methods Enzymol 2019; 621:261-279. [PMID: 31128783 DOI: 10.1016/bs.mie.2019.02.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Glycosyltransferases (GTs) catalyze the transfer of a sugar moiety from nucleotide-sugar or lipid-phospho-sugar donors to a wide range of acceptor substrates, generating a remarkable amount of structural diversity in biological systems. Glycosyl transfer reactions can proceed with either inversion or retention of the anomeric configuration with respect to the sugar donor substrate. In this chapter, we discuss the application of a quick soaking method of substrates and products into protein crystals to visualize native ternary complexes of retaining glycosyltransferases. The crystal structures provide different snapshots of the catalytic cycle, including the Michaelis complex. During this sequence of events, we visualize how the enzyme guides the substrates into the reaction center where the glycosyl transfer reaction takes place, and unveil the mechanism of product release, involving multiple conformational changes not only in the substrates and products but also in the enzyme. The methodology described here provides unprecedented insights into the catalytic mechanism of glycosyltransferases at the molecular level, and can be applied to the study a myriad of enzymatic mediated reactions.
Collapse
Affiliation(s)
- David Albesa-Jové
- Structural Biology Unit, CIC bioGUNE, Derio, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | | | | | - Marcelo E Guerin
- Structural Biology Unit, CIC bioGUNE, Derio, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
| |
Collapse
|
6
|
Albesa-Jové D, Romero-García J, Sancho-Vaello E, Contreras FX, Rodrigo-Unzueta A, Comino N, Carreras-González A, Arrasate P, Urresti S, Biarnés X, Planas A, Guerin ME. Structural Snapshots and Loop Dynamics along the Catalytic Cycle of Glycosyltransferase GpgS. Structure 2017. [PMID: 28625787 DOI: 10.1016/j.str.2017.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Glycosyltransferases (GTs) play a central role in nature. They catalyze the transfer of a sugar moiety to a broad range of acceptor substrates. GTs are highly selective enzymes, allowing the recognition of subtle structural differences in the sequences and stereochemistry of their sugar and acceptor substrates. We report here a series of structural snapshots of the reaction center of the retaining glucosyl-3-phosphoglycerate synthase (GpgS). During this sequence of events, we visualize how the enzyme guides the substrates into the reaction center where the glycosyl transfer reaction takes place, and unveil the mechanism of product release, involving multiple conformational changes not only in the substrates/products but also in the enzyme. The structural data are further complemented by metadynamics free-energy calculations, revealing how the equilibrium of loop conformations is modulated along these itineraries. The information reported here represent an important contribution for the understanding of GT enzymes at the molecular level.
Collapse
Affiliation(s)
- David Albesa-Jové
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Javier Romero-García
- Laboratory of Biochemistry, Bioengineering Department, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona 08017, Spain
| | - Enea Sancho-Vaello
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | - F-Xabier Contreras
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Ane Rodrigo-Unzueta
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | - Natalia Comino
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain
| | - Ana Carreras-González
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain
| | - Pedro Arrasate
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | - Saioa Urresti
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | - Xevi Biarnés
- Laboratory of Biochemistry, Bioengineering Department, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona 08017, Spain
| | - Antoni Planas
- Laboratory of Biochemistry, Bioengineering Department, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona 08017, Spain
| | - Marcelo E Guerin
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, Ed. 801A, 48160 Derio, Spain; Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain; IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain.
| |
Collapse
|
7
|
Kumar G, Guan S, Frantom PA. Biochemical characterization of the retaining glycosyltransferase glucosyl-3-phosphoglycerate synthase from Mycobacterium tuberculosis. Arch Biochem Biophys 2014; 564:120-7. [PMID: 25317963 DOI: 10.1016/j.abb.2014.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/03/2014] [Accepted: 10/06/2014] [Indexed: 11/15/2022]
Abstract
Glucosyl-3-phosphoglycerate synthase (GpgS) catalyzes the first step in the biosynthesis of glucosyl glycerate, the putative precursor used in building methylated polysaccharides in mycobacteria. Enzymes from Mycobacterium tuberculosis (MtGpgS) and related species have been structurally characterized and subjected to basic kinetic analyses, but more in-depth kinetic analysis is currently lacking. Dead-end inhibition studies with MtGpgS suggest an ordered kinetic mechanism with 3-phosphoglycerate (3-PGA) binding first, followed by UDP-glucose, in contrast to previous reports. At higher concentrations, 3-PGA exhibits competitive substrate inhibition vs. UDP-glucose, suggesting 3-PGA can bind to either binding site on the enzyme. Parabolic noncompetitive inhibition plots by a 3-PGA analog also support this conclusion. The effect of varying pH on the catalytic parameters indicates single ionizable residue involved catalysis (pKa=6.3) that must be deprotonated for full activity. A solvent kinetic isotope effect of 2.0±0.3 on kcat is consistent with a proton in flight during the rate-determining step. Site-directed mutagenesis studies identify several residues critical for interactions with substrates. Although the residues are conserved among other glycosyltransferase families catalyzing similar reactions, the effect of substitutions varies between families suggesting that conserved areas play different catalytic roles in each family.
Collapse
Affiliation(s)
- Garima Kumar
- Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, AL 35487, USA
| | - Siqi Guan
- Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, AL 35487, USA
| | - Patrick A Frantom
- Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, AL 35487, USA.
| |
Collapse
|
8
|
Structure-function features of a Mycoplasma glycolipid synthase derived from structural data integration, molecular simulations, and mutational analysis. PLoS One 2013; 8:e81990. [PMID: 24312618 PMCID: PMC3849446 DOI: 10.1371/journal.pone.0081990] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/18/2013] [Indexed: 11/19/2022] Open
Abstract
Glycoglycerolipids are structural components of mycoplasma membranes with a fundamental role in membrane properties and stability. Their biosynthesis is mediated by glycosyltransferases (GT) that catalyze the transfer of glycosyl units from a sugar nucleotide donor to diacylglycerol. The essential function of glycolipid synthases in mycoplasma viability, and the absence of glycoglycerolipids in animal host cells make these GT enzymes a target for drug discovery by designing specific inhibitors. However, rational drug design has been hampered by the lack of structural information for any mycoplasma GT. Most of the annotated GTs in pathogenic mycoplasmas belong to family GT2. We had previously shown that MG517 in Mycoplasma genitalium is a GT-A family GT2 membrane-associated glycolipid synthase. We present here a series of structural models of MG517 obtained by homology modeling following a multiple-template approach. The models have been validated by mutational analysis and refined by long scale molecular dynamics simulations. Based on the models, key structure-function relationships have been identified: The N-terminal GT domain has a GT-A topology that includes a non-conserved variable region involved in acceptor substrate binding. Glu193 is proposed as the catalytic base in the GT mechanism, and Asp40, Tyr126, Tyr169, Ile170 and Tyr218 define the substrates binding site. Mutation Y169F increases the enzyme activity and significantly alters the processivity (or sequential transferase activity) of the enzyme. This is the first structural model of a GT-A glycoglycerolipid synthase and provides preliminary insights into structure and function relationships in this family of enzymes.
Collapse
|
9
|
Biotransformation of 4-sec-butylphenol by Gram-positive bacteria of the genera Mycobacterium and Nocardia including modifications on the alkyl chain and the hydroxyl group. Appl Microbiol Biotechnol 2013; 97:8329-39. [PMID: 23912120 DOI: 10.1007/s00253-013-5127-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/10/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
Abstract
The environmental pollutant 4-sec-butylphenol (4-sec-BP) which possesses estrogenic properties was transformed by the aerobic Gram-positive bacteria Mycobacterium neoaurum and Nocardia cyriacigeorgica into three main products (P1-P3) which were isolated and structurally characterized in detail. Two of them were products of a process resembling anaerobic metabolism of alkylphenols based on modifications of the alkyl side chain of 4-sec-BP. The first product (P1) was identified as 4-(2-hydroxy-1-methylpropyl)-phenol. The second product P2 was isolated as a mixture of at least four structures which could be identified as I 4-sec-butylidenecyclohexa-2,5-dienone; II 4-(1-methylenepropyl)-phenol; III 4-(1-methylpropenyl)-phenol; and IV 4-(1-methylallyl)-phenol. In contrast to P1 and P2, the third product (P3) resulted from a modification of the hydroxyl group of 4-sec-BP. This product was only formed by M. neoaurum and was identified as the glucoside conjugate 4-sec-butylphenol-α-D-glucopyranoside. Since in general, fungi synthesize sugar conjugates to detoxify hazardous pollutants, the formation of this conjugate is a peculiarity of M. neoaurum. Thus, altogether, six products were formed from 4-sec-BP and different transformation pathways are introduced. The hydroxylating and glucosylating capacity of the characterized bacteria open up applications in environmental protection.
Collapse
|
10
|
Malik V, Black GW. Structural, functional, and mutagenesis studies of UDP-glycosyltransferases. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 87:87-115. [PMID: 22607753 DOI: 10.1016/b978-0-12-398312-1.00004-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
The biosynthesis of the complex carbohydrates that govern many cellular functions requires the action of a diverse range of selective glycosyltransferases (GTs). Uridine diphosphate sugar-utilizing GTs (UGTs) account for the majority of characterized GTs. GTs have been classified into families (currently 92) based on amino-acid sequence similarity. However, as amino-acid sequence similarity cannot reliable predict catalytic mechanism, GTs have also been grouped into four clans based on catalytic mechanism and structural fold. GTs catalyze glycosidic bond formation with two possible stereochemical outcomes: inversion or retention of anomeric configuration. All UGTs also belong to one of two distinct structural folds, GT-A and GT-B. UGTs have conserved residues that are associated with nucleotide diphosphate sugar recognition and acceptor recognition. UGT diversification has been performed using in vitro DNA recombination, domain swapping, and random mutagenesis.
Collapse
Affiliation(s)
- Vatsala Malik
- School of Life Sciences, Department of Biomedical Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | | |
Collapse
|
11
|
Urresti S, Albesa-Jové D, Schaeffer F, Pham HT, Kaur D, Gest P, van der Woerd MJ, Carreras-González A, López-Fernández S, Alzari PM, Brennan PJ, Jackson M, Guerin ME. Mechanistic insights into the retaining glucosyl-3-phosphoglycerate synthase from mycobacteria. J Biol Chem 2012; 287:24649-61. [PMID: 22637481 DOI: 10.1074/jbc.m112.368191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Considerable progress has been made in recent years in our understanding of the structural basis of glycosyl transfer. Yet the nature and relevance of the conformational changes associated with substrate recognition and catalysis remain poorly understood. We have focused on the glucosyl-3-phosphoglycerate synthase (GpgS), a "retaining" enzyme, that initiates the biosynthetic pathway of methylglucose lipopolysaccharides in mycobacteria. Evidence is provided that GpgS displays an unusually broad metal ion specificity for a GT-A enzyme, with Mg(2+), Mn(2+), Ca(2+), Co(2+), and Fe(2+) assisting catalysis. In the crystal structure of the apo-form of GpgS, we have observed that a flexible loop adopts a double conformation L(A) and L(I) in the active site of both monomers of the protein dimer. Notably, the L(A) loop geometry corresponds to an active conformation and is conserved in two other relevant states of the enzyme, namely the GpgS·metal·nucleotide sugar donor and the GpgS·metal·nucleotide·acceptor-bound complexes, indicating that GpgS is intrinsically in a catalytically active conformation. The crystal structure of GpgS in the presence of Mn(2+)·UDP·phosphoglyceric acid revealed an alternate conformation for the nucleotide sugar β-phosphate, which likely occurs upon sugar transfer. Structural, biochemical, and biophysical data point to a crucial role of the β-phosphate in donor and acceptor substrate binding and catalysis. Altogether, our experimental data suggest a model wherein the catalytic site is essentially preformed, with a few conformational changes of lateral chain residues as the protein proceeds along the catalytic cycle. This model of action may be applicable to a broad range of GT-A glycosyltransferases.
Collapse
Affiliation(s)
- Saioa Urresti
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea, Barrio Sarriena s/n, Leioa, Bizkaia, 48940, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Topological and mutational analysis of Saccharomyces cerevisiae Fks1. EUKARYOTIC CELL 2012; 11:952-60. [PMID: 22581527 DOI: 10.1128/ec.00082-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fks1, with orthologs in nearly all fungi as well as plants and many protists, plays a central role in fungal cell wall formation as the putative catalytic component of β-1,3-glucan synthase. It is also the target for an important new antifungal group, the echinocandins, as evidenced by the localization of resistance-conferring mutations to Fks1 hot spots 1, 2, and 3 (residues 635 to 649, 1354 to 1361, and 690 to 700, respectively). Since Fks1 is an integral membrane protein and echinocandins are cyclic peptides with lipid tails, Fks1 topology is key to understanding its function and interaction with echinocandins. We used hemagglutinin (HA)-Suc2-His4C fusions to C-terminally truncated Saccharomyces cerevisiae Fks1 to experimentally define its topology and site-directed mutagenesis to test function of selected residues. Of the 15 to 18 transmembrane helices predicted in silico for Fks1 from evolutionarily diverse fungi, 13 were experimentally confirmed. The N terminus (residues 1 to 445) is cytosolic and the C terminus (residues 1823 to 1876) external; both are essential to Fks1 function. The cytosolic central domain (residues 715 to 1294) includes newly recognized homology to glycosyltransferases, and residues potentially involved in substrate UDP-glucose binding and catalysis are essential. All three hot spots are external, with hot spot 1 adjacent to and hot spot 3 largely embedded within the outer leaflet of the membrane. This topology suggests a model in which echinocandins interact through their lipid tails with hot spot 3 and through their cyclic peptides with hot spots 1 and 2.
Collapse
|
13
|
Nielsen MM, Suits MDL, Yang M, Barry CS, Martinez-Fleites C, Tailford LE, Flint JE, Dumon C, Davis BG, Gilbert HJ, Davies GJ. Substrate and metal ion promiscuity in mannosylglycerate synthase. J Biol Chem 2011; 286:15155-64. [PMID: 21288903 PMCID: PMC3083222 DOI: 10.1074/jbc.m110.199844] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 01/24/2011] [Indexed: 11/06/2022] Open
Abstract
The enzymatic transfer of the sugar mannose from activated sugar donors is central to the synthesis of a wide range of biologically significant polysaccharides and glycoconjugates. In addition to their importance in cellular biology, mannosyltransferases also provide model systems with which to study catalytic mechanisms of glycosyl transfer. Mannosylglycerate synthase (MGS) catalyzes the synthesis of α-mannosyl-D-glycerate using GDP-mannose as the preferred donor species, a reaction that occurs with a net retention of anomeric configuration. Past work has shown that the Rhodothermus marinus MGS, classified as a GT78 glycosyltransferase, displays a GT-A fold and performs catalysis in a metal ion-dependent manner. MGS shows very unusual metal ion dependences with Mg(2+) and Ca(2+) and, to a lesser extent, Mn(2+), Ni(2+), and Co(2+), thus facilitating catalysis. Here, we probe these dependences through kinetic and calorimetric analyses of wild-type and site-directed variants of the enzyme. Mutation of residues that interact with the guanine base of GDP are correlated with a higher k(cat) value, whereas substitution of His-217, a key component of the metal coordination site, results in a change in metal specificity to Mn(2+). Structural analyses of MGS complexes not only provide insight into metal coordination but also how lactate can function as an alternative acceptor to glycerate. These studies highlight the role of flexible loops in the active center and the subsequent coordination of the divalent metal ion as key factors in MGS catalysis and metal ion dependence. Furthermore, Tyr-220, located on a flexible loop whose conformation is likely influenced by metal binding, also plays a critical role in substrate binding.
Collapse
Affiliation(s)
- Morten M. Nielsen
- From the Institute for Cell and Molecular Biosciences, Newcastle University, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Michael D. L. Suits
- the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Min Yang
- the Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom, and
| | - Conor S. Barry
- the Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom, and
| | - Carlos Martinez-Fleites
- the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Louise E. Tailford
- From the Institute for Cell and Molecular Biosciences, Newcastle University, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - James E. Flint
- From the Institute for Cell and Molecular Biosciences, Newcastle University, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Claire Dumon
- From the Institute for Cell and Molecular Biosciences, Newcastle University, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Benjamin G. Davis
- the Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom, and
| | - Harry J. Gilbert
- From the Institute for Cell and Molecular Biosciences, Newcastle University, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
- the University of Georgia Complex Carbohydrate Research Center, Athens, Georgia 30602-4712
| | - Gideon J. Davies
- the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| |
Collapse
|
14
|
Luley-Goedl C, Nidetzky B. Glycosides as compatible solutes: biosynthesis and applications. Nat Prod Rep 2011; 28:875-96. [DOI: 10.1039/c0np00067a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
15
|
Vembaiyan K, Pearcey JA, Bhasin M, Lowary TL, Zou W. Synthesis of sugar-amino acid-nucleosides as potential glycosyltransferase inhibitors. Bioorg Med Chem 2010; 19:58-66. [PMID: 21167722 DOI: 10.1016/j.bmc.2010.11.044] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 11/18/2010] [Accepted: 11/22/2010] [Indexed: 11/29/2022]
Abstract
Sugar-amino acid-nucleosides (SAAN) were synthesized to mimic glycosyl nucleotide donors based on the hypothesis that a basic amino acid may interact with carboxylate groups of the enzyme in a manner similar to the diphosphate metal ion complex. C-Glycoside analogues of the d-galactopyranose or l-arabinofuranose ring systems, and four amino acids (lysine, glutamine, tryptophan, and histidine), were chosen for this study. The targets were synthesized and tested against GlfT2, a galactofuranosyltransferase essential for cell wall galactan biosynthesis in Mycobacterium tuberculosis. The inhibition assay showed that analogues containing histidine and tryptophan are moderate inhibitors of GlfT2.
Collapse
Affiliation(s)
- Kannan Vembaiyan
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6
| | | | | | | | | |
Collapse
|
16
|
Empadinhas N, Pereira PJB, Albuquerque L, Costa J, Sá-Moura B, Marques AT, Macedo-Ribeiro S, da Costa MS. Functional and structural characterization of a novel mannosyl-3-phosphoglycerate synthase from Rubrobacter xylanophilus reveals its dual substrate specificity. Mol Microbiol 2010; 79:76-93. [PMID: 21166895 DOI: 10.1111/j.1365-2958.2010.07432.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Rubrobacter xylanophilus is the only actinobacterium known to accumulate the organic solute mannosylglycerate (MG); moreover, the accumulation of MG is constitutive. The key enzyme for MG synthesis, catalysing the conversion of GDP-mannose (GDP-Man) and D-3-phosphoglycerate (3-PGA) into the phosphorylated intermediate mannosyl-3-phosphoglycerate and GDP, was purified from R. xylanophilus cell extracts and the corresponding gene was expressed in E. coli. Despite the related solute glucosylglycerate (GG) having never been detected in R. xylanophilus, the cell extracts and the pure recombinant mannosyl-3-phosphoglycerate synthase (MpgS) could also synthesize glucosyl-3-phosphoglycerate (GPG), the precursor of GG, in agreement with the higher homology of the novel MpgS towards GPG-synthesizing mycobacterial glucosyl-3-phosphoglycerate synthases (GpgS) than towards MpgSs from hyper/thermophiles, known to accumulate MG under salt or thermal stress. To understand the specificity and substrate ambiguity of this novel enzyme, we determined the crystal structure of the unliganded MpgS and of its complexes with the nucleotide and sugar donors, at 2.2, 2.8 and 2.5 Å resolution respectively. The first three-dimensional structures of a protein from this extremely gamma-radiation-resistant thermophile here reported show that MpgS (GT81 family) contains a GT-A like fold and clearly explain its nucleotide and sugar-donor specificity. In the GDP-Man complex, a flexible loop ((254) RQNRHQ(259) ), located close to the active site moves towards the incoming sugar moiety, providing the ligands for both magnesium ion co-ordination and sugar binding. A triple mutant of R. xylanophilus MpgS, mimicking the (206) PLAGE(210) loop stabilizing hydrogen bond network observed for mycobacterial GpgSs, reduces significantly the affinity to GDP-Man, implicating this loop in the sugar-donor discrimination.
Collapse
Affiliation(s)
- Nuno Empadinhas
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Gonçalves S, Borges N, Esteves AM, Victor BL, Soares CM, Santos H, Matias PM. Structural analysis of Thermus thermophilus HB27 mannosyl-3-phosphoglycerate synthase provides evidence for a second catalytic metal ion and new insight into the retaining mechanism of glycosyltransferases. J Biol Chem 2010; 285:17857-68. [PMID: 20356840 PMCID: PMC2878549 DOI: 10.1074/jbc.m109.095976] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 03/17/2010] [Indexed: 11/06/2022] Open
Abstract
Mannosyl-3-phosphoglycerate synthase is a glycosyltransferase involved in the two-step synthetic pathway of mannosylglycerate, a compatible solute that accumulates in response to salt and/or heat stresses in many microorganisms thriving in hot environments. The three-dimensional structure of mannosyl-3-phosphoglycerate synthase from Thermus thermophilus HB27 in its binary complex form, with GDP-alpha-D-mannose and Mg(2+), shows a second metal binding site, about 6 A away from the mannose moiety. Kinetic and mutagenesis studies have shown that this metal site plays a role in catalysis. Additionally, Asp(167) in the DXD motif is found within van der Waals contact distance of the C1' atom in the mannopyranose ring, suggesting its action as a catalytic nucleophile, either in the formation of a glycosyl-enzyme intermediate according to the double-displacement S(N)2 reaction mechanism or in the stabilization of the oxocarbenium ion-like intermediate according to the D(N)*A(Nss) (S(N)i-like) reaction mechanism. We propose that either mechanism may occur in retaining glycosyltransferases with a GT-A fold, and, based on the gathered structural information, we identified an extended structural signature toward a common scaffold between the inverting and retaining glycosyltransferases.
Collapse
Affiliation(s)
- Susana Gonçalves
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Nuno Borges
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Ana M. Esteves
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Bruno L. Victor
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Cláudio M. Soares
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Helena Santos
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Pedro M. Matias
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| |
Collapse
|
18
|
Hashimoto K, Madej T, Bryant SH, Panchenko AR. Functional states of homooligomers: insights from the evolution of glycosyltransferases. J Mol Biol 2010; 399:196-206. [PMID: 20381499 DOI: 10.1016/j.jmb.2010.03.059] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/29/2010] [Accepted: 03/29/2010] [Indexed: 02/02/2023]
Abstract
Glycosylation is an important aspect of epigenetic regulation. Glycosyltransferase is a key enzyme in the biosynthesis of glycans, which glycosylates more than half of all proteins in eukaryotes and is involved in a wide range of biological processes. It has been suggested previously that homooligomerization in glycosyltransferases and other proteins might be crucial for their function. In this study, we explore functional homooligomeric states of glycosyltransferases in various organisms, trace their evolution, and perform comparative analyses to find structural features that can mediate or disrupt the formation of different homooligomers. First, we make a structure-based classification of the diverse superfamily of glycosyltransferases and confirm that the majority of the structures are indeed clustered into the GT-A or GT-B folds. We find that homooligomeric glycosyltransferases appear to be as ancient as monomeric glycosyltransferases and go back in evolution to the last universal common ancestor (LUCA). Moreover, we show that interface residues have significant bias to be gapped out or unaligned in the monomers, implying that they might represent features crucial for oligomer formation. Structural analysis of these features reveals that the majority of them represent loops, terminal regions, and helices, indicating that these secondary-structure elements mediate the formation of glycosyltransferases' homooligomers and directly contribute to the specific binding. We also observe relatively short protein regions that disrupt the homodimer interactions, although such cases are rare. These results suggest that relatively small structural changes in the nonconserved regions may contribute to the formation of different functional oligomeric states and might be important in regulation of enzyme activity through homooligomerization.
Collapse
Affiliation(s)
- Kosuke Hashimoto
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 8600 Rockville Pike, Building 38A 8S814, Bethesda, MD 20894, USA
| | | | | | | |
Collapse
|
19
|
Kaur D, Guerin ME, Skovierová H, Brennan PJ, Jackson M. Chapter 2: Biogenesis of the cell wall and other glycoconjugates of Mycobacterium tuberculosis. ADVANCES IN APPLIED MICROBIOLOGY 2009; 69:23-78. [PMID: 19729090 DOI: 10.1016/s0065-2164(09)69002-x] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The re-emergence of tuberculosis in its present-day manifestations - single, multiple and extensive drug-resistant forms and as HIV-TB coinfections - has resulted in renewed research on fundamental questions such as the nature of the organism itself, Mycobacterium tuberculosis, the molecular basis of its pathogenesis, definition of the immunological response in animal models and humans, and development of new intervention strategies such as vaccines and drugs. Foremost among these developments has been the precise chemical definition of the complex and distinctive cell wall of M. tuberculosis, elucidation of the relevant pathways and underlying genetics responsible for the synthesis of the hallmark moieties of the tubercle bacillus such as the mycolic acid-arabinogalactan-peptidoglycan complex, the phthiocerol- and trehalose-containing effector lipids, the phosphatidylinositol-containing mannosides, lipomannosides and lipoarabinomannosides, major immunomodulators, and others. In this review, the laboratory personnel who have been the focal point of some to these developments review recent progress towards a comprehensive understanding of the basic physiology and functions of the cell wall of M. tuberculosis.
Collapse
Affiliation(s)
- Devinder Kaur
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, CO 80523-1682, USA
| | | | | | | | | |
Collapse
|
20
|
Carlier A, Burbank L, von Bodman SB. Identification and characterization of three novel EsaI/EsaR quorum-sensing controlled stewartan exopolysaccharide biosynthetic genes in Pantoea stewartii ssp. stewartii. Mol Microbiol 2009; 74:903-13. [PMID: 19843225 DOI: 10.1111/j.1365-2958.2009.06906.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Aurélien Carlier
- Institut für Pflanzenbiologie, Universität Zürich, Zürich, Switzerland
| | | | | |
Collapse
|
21
|
Kaur D, Pham H, Larrouy-Maumus G, Rivière M, Vissa V, Guerin ME, Puzo G, Brennan PJ, Jackson M. Initiation of methylglucose lipopolysaccharide biosynthesis in mycobacteria. PLoS One 2009; 4:e5447. [PMID: 19421329 PMCID: PMC2674218 DOI: 10.1371/journal.pone.0005447] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 04/10/2009] [Indexed: 11/19/2022] Open
Abstract
Background Mycobacteria produce two unique families of cytoplasmic polymethylated polysaccharides - the methylglucose lipopolysaccharides (MGLPs) and the methylmannose polysaccharides (MMPs) - the physiological functions of which are still poorly defined. Towards defining the roles of these polysaccharides in mycobacterial physiology, we generated knock-out mutations of genes in their putative biosynthetic pathways. Methodology/Principal Findings We report here on the characterization of the Rv1208 protein of Mycobacterium tuberculosis and its ortholog in Mycobacterium smegmatis (MSMEG_5084) as the enzymes responsible for the transfer of the first glucose residue of MGLPs. Disruption of MSMEG_5084 in M. smegmatis resulted in a dramatic decrease in MGLP synthesis directly attributable to the almost complete abolition of glucosyl-3-phosphoglycerate synthase activity in this strain. Synthesis of MGLPs in the mutant was restored upon complementation with wild-type copies of the Rv1208 gene from M. tuberculosis or MSMEG_5084 from M. smegmatis. Conclusions/Significance This is the first evidence linking Rv1208 to MGLP biosynthesis. Thus, the first step in the initiation of MGLP biosynthesis in mycobacteria has been defined, and subsequent steps can be inferred.
Collapse
Affiliation(s)
- Devinder Kaur
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ha Pham
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Gérald Larrouy-Maumus
- Département «Mécanismes Moléculaires des Infections Mycobactériennes», Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie et Biologie Structurale (UMR 5089), Université de Toulouse III, Toulouse, France
| | - Michel Rivière
- Département «Mécanismes Moléculaires des Infections Mycobactériennes», Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie et Biologie Structurale (UMR 5089), Université de Toulouse III, Toulouse, France
| | - Varalakshmi Vissa
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Marcelo E. Guerin
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Germain Puzo
- Département «Mécanismes Moléculaires des Infections Mycobactériennes», Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie et Biologie Structurale (UMR 5089), Université de Toulouse III, Toulouse, France
| | - Patrick J. Brennan
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
| |
Collapse
|
22
|
Jackson M, Brennan PJ. Polymethylated polysaccharides from Mycobacterium species revisited. J Biol Chem 2008; 284:1949-53. [PMID: 18786916 DOI: 10.1074/jbc.r800047200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mycobacteria produce two sets of unusual polymethylated polysaccharides, the 3-O-methylmannose polysaccharides and the 6-O-methylglucose lipopolysaccharides. Both polysaccharides localize to the cytoplasm, where they have been postulated to regulate fatty acid metabolism due to their ability to form stable 1:1 complexes with fatty acyl chains. Physiological evidence for this assumption is lacking, however. Recent advances in our knowledge of the processes underlying sugar transfer in mycobacteria, together with the availability of genome sequences and tools for the genetic manipulation of these microorganisms, have opened the way to the elucidation of the biosynthetic pathways and biological functions of these unique carbohydrates.
Collapse
Affiliation(s)
- Mary Jackson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, USA
| | | |
Collapse
|