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Malaga W, Constant P, Euphrasie D, Cataldi A, Daffé M, Reyrat JM, Guilhot C. Deciphering the genetic bases of the structural diversity of phenolic glycolipids in strains of the Mycobacterium tuberculosis complex. J Biol Chem 2008; 283:15177-84. [PMID: 18390543 PMCID: PMC3258887 DOI: 10.1074/jbc.m710275200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 04/03/2008] [Indexed: 11/06/2022] Open
Abstract
Phenolic glycolipids (PGL) play a major role in the virulence of mycobacteria, notably in strains of the Mycobacterium tuberculosis complex and in Mycobacterium leprae. The structure of the carbohydrate domain of these compounds is highly variable, and the genetic bases for these variations remain unknown. We demonstrated that the monoglycosylated PGL formed by Mycobacterium bovis differs from the triglycosylated PGL synthesized by M. tuberculosis (PGL-tb) because of the following two genetic defects: a frameshift mutation within the gene Rv2958c, encoding a glycosyltransferase involved in the transfer of the second rhamnosyl residue of the PGL-tb, and a deletion of a region that encompasses two genes, which encode a GDP-D-mannose 4,6-dehydratase and a GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase/reductase, required for the formation of activated L-fucose. Expression of these three genes in M. bovis BCG allowed synthesis of PGL-tb in this recombinant strain. Additionally, we showed that all M. bovis, Mycobacterium microti, Mycobacterium pinnipedii, and some Mycobacterium africanum strains harbor the same frameshift mutation in their Rv2958c orthologs. Consistently, the structure of PGLs purified from M. africanum (harboring the Rv2958c mutation) and M. pinnipedii strains revealed that these compounds are monoglycosylated PGL. These findings explain the specificity of PGL-tb production by some strains of the M. tuberculosis complex and have important implications for our understanding of the evolution of this complex.
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Affiliation(s)
- Wladimir Malaga
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
| | - Patricia Constant
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
| | - Daniel Euphrasie
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
| | - Angel Cataldi
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
| | - Mamadou Daffé
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
| | - Jean-Marc Reyrat
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
| | - Christophe Guilhot
- Université Paul Sabatier and CNRS, Institut de Pharmacologie et Biologie Structurale (Unité Mixte de Recherche 5089), Département “Mécanismes Moléculaires des Infections Mycobactériennes,” 205 Route de Narbonne, 31077 Toulouse Cedex 4, France, Université Paris Descartes, Faculté de Médecine René Descartes, Inserm U570, Unité de Pathogénie des Infections Systémiques, 75730 Paris Cedex 15, France, and Institute of Biotechnology, CNIA-INTA, 1712 Castelar, Argentina
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Pérez E, Constant P, Lemassu A, Laval F, Daffé M, Guilhot C. Characterization of Three Glycosyltransferases Involved in the Biosynthesis of the Phenolic Glycolipid Antigens from the Mycobacterium tuberculosis Complex. J Biol Chem 2004; 279:42574-83. [PMID: 15292272 DOI: 10.1074/jbc.m406246200] [Citation(s) in RCA: 56] [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
Mycobacterium tuberculosis and Mycobacterium leprae, the two main mycobacterial pathogens in humans, produce highly specific long chain beta-diols, the dimycocerosates of phthiocerol, and structurally related phenolic glycolipid (PGL) antigens, which are important virulence factors. In addition, M. tuberculosis also secretes glycosylated p-hydroxybenzoic acid methyl esters (p-HBAD) that contain the same carbohydrate moiety as the species-specific PGL of M. tuberculosis (PGL-tb). The genes involved in the biosynthesis of these compounds in M. tuberculosis are grouped on a 70-kilobase chromosomal fragment containing three genes encoding putative glycosyltransferases: Rv2957, Rv2958c, and Rv2962c. To determine the functions of these genes, three recombinant M. tuberculosis strains, in which these genes were individually inactivated, were constructed and biochemically characterized. Our results demonstrated that (i) the biosynthesis of PGL-tb and p-HBAD involves common enzymatic steps, (ii) the Rv2957, Rv2958c, and Rv2962c genes are involved in the formation of the glycosyl moiety of the two classes of molecules, and (iii) the product of Rv2962c catalyzes the transfer of a rhamnosyl residue onto p-hydroxybenzoic acid ethyl ester or phenolphthiocerol dimycocerosates, whereas the products of Rv2958c and Rv2957 add a second rhamnosyl unit and a fucosyl residue to form the species-specific triglycosyl appendage of PGL-tb and p-HBAD. The recombinant strains produced provide the tools to study the role of the carbohydrate domain of PGL-tb and p-HBAD in M. tuberculosis pathogenesis.
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Affiliation(s)
- Esther Pérez
- Département "Mécanismes Moléculaires des Infections Mycobactériennes," Institut de Pharmacologie et Biologie Structurale, CNRS and Université Paul Sabatier (Unité Mixte de Recherche 5089), 205 route de Narbonne, 31077 Toulouse Cedex, France
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Constant P, Perez E, Malaga W, Lanéelle MA, Saurel O, Daffé M, Guilhot C. Role of the pks15/1 gene in the biosynthesis of phenolglycolipids in the Mycobacterium tuberculosis complex. Evidence that all strains synthesize glycosylated p-hydroxybenzoic methyl esters and that strains devoid of phenolglycolipids harbor a frameshift mutation in the pks15/1 gene. J Biol Chem 2002; 277:38148-58. [PMID: 12138124 DOI: 10.1074/jbc.m206538200] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Diesters of phthiocerol and phenolphthiocerol are important virulence factors of Mycobacterium tuberculosis and Mycobacterium leprae, the two main mycobacterial pathogens in humans. They are both long-chain beta-diols, and their biosynthetic pathway is beginning to be elucidated. Although the two classes of molecules share a common lipid core, phthiocerol diesters have been found in all the strains of the M. tuberculosis complex examined although phenolphthiocerol diesters are produced by only a few groups of strains. To address the question of the origin of this diversity 8 reference strains and 10 clinical isolates of M. tuberculosis were analyzed. We report the presence of glycosylated p-hydroxybenzoic acid methyl esters, structurally related to the type-specific phenolphthiocerol glycolipids, in the culture media of all reference strains of M. tuberculosis, suggesting that the strains devoid of phenolphthiocerol derivatives are unable to elongate the putative p-hydroxybenzoic acid precursor. We also show that all the strains of M. tuberculosis examined and deficient in the production of phenolphthiocerol derivatives are natural mutants with a frameshift mutation in pks15/1 whereas a single open reading frame for pks15/1 is found in Mycobacterium bovis BCG, M. leprae, and strains of M. tuberculosis that produce phenolphthiocerol derivatives. Complementation of the H37Rv strain of M. tuberculosis, which is devoid of phenolphthiocerol derivatives, with the fused pks15/1 gene from M. bovis BCG restored phenolphthiocerol glycolipids production. Conversely, disruption of the pks15/1 gene in M. bovis BCG led to the abolition of the synthesis of type-specific phenolphthiocerol glycolipid. These data indicate that Pks15/1 is involved in the elongation of p-hydroxybenzoic acid to give p-hydroxyphenylalkanoates, which in turn are converted, presumably by the PpsA-E synthase, to phenolphthiocerol derivatives.
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Affiliation(s)
- Patricia Constant
- Département Mécanismes Moléculaires des Infections Mycobactériennes, Institut de Pharmacologie et Biologie Structurale, CNRS and Université Paul Sabatier (Unité Mixte de Recherche 5089), 205 route de Narbonne, 31077 Toulouse Cedex, France
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Abstract
The review discusses current knowledge of the biosynthesis, composition and arrangement of the mycobacterial envelope, describes the biological activities of the constituents and considers how these activities may be relevant to the pathology of mycobacterial disease. The envelope possesses three structural components: plasma membrane, wall and capsule. Although the major biomolecules occurring in each of these parts are known, the distribution of numerous minor substances is poorly understood; an attempt has been made to assign them to particular positions on rational grounds. The plasma membrane appears to be a typical bacterial membrane but, though vital to the mycobacterium, probably plays little part in pathological processes. The wall partly resembles a Gram-positive wall, but is unusual in having a layer of lipid (mycolate esters) which is probably arranged to form a permeability barrier to polar molecules. The capsule, whose chemical composition has only recently been recognized, consists of polysaccharide and protein with traces of lipid; the arrangement of these components is imperfectly understood. Constituents of all parts of the envelope have biological activities which may be relevant. The likely importance of these activities in the overall effect of the envelope is considered.
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Affiliation(s)
- M Daffé
- Institut de Pharmacologie et de Biologie Structurale, Toulouse, France
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Azad AK, Sirakova TD, Rogers LM, Kolattukudy PE. Targeted replacement of the mycocerosic acid synthase gene in Mycobacterium bovis BCG produces a mutant that lacks mycosides. Proc Natl Acad Sci U S A 1996; 93:4787-92. [PMID: 8643481 PMCID: PMC39357 DOI: 10.1073/pnas.93.10.4787] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A single gene (mas) encodes the multifunctional enzyme that catalyzes the synthesis of very long chain multiple methyl branched fatty acids called mycocerosic acids that are present only in slow-growing pathogenic mycobacteria and are thought to be important for pathogenesis. To achieve a targeted disruption of mas, an internal 2-kb segment of this gene was replaced with approximately the same size hygromycin-resistance gene (hyg), such that hyg was flanked by 4.7- and 1.4-kb segments of mas. Transformation of Mycobacterium bovis BCG with this construct in a plasmid that cannot replicate in mycobacteria yielded hygromycin-resistant transformants. Screening of 38 such transformants by PCR revealed several transformants representing homologous recombination with single crossover and one with double crossover. With primers representing the hyg termini and those representing the mycobacterial genome segments outside that used to make the transformation construct, the double-crossover mutant yielded PCR products expected from either side of hyg. Gene replacement was further confirmed by the absence of the vector and the 2-kb segment of mas replaced by hyg from the genome of the mutant. Thin-layer and radio-gas chromatographic analyses of the lipids derived from [1-14C]propionate showed that the mutant was incapable of synthesizing mycocerosic acids and mycosides. Thus, homologous recombination with double crossover was achieved in a slow-growing mycobacterium with an intron-containing RecA. The resulting mas-disrupted mutant should allow testing of the postulated roles of mycosides in pathogenesis.
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Affiliation(s)
- A K Azad
- Neurobiotechnology Center, The Ohio State University, Columbus, 43210, USA
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