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.
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.
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.
Patricia
P
Constant
Esther
E
Perez
Wladimir
W
Malaga
Marie-Antoinette
MA
Lanéelle
Olivier
O
Saurel
Mamadou
M
Daffé
Christophe
C
Guilhot
D000818:Animals; D000942:Antigens, Bacterial / Q000378:metabolism; D001483:Base Sequence; D004952:Esters / Q000737:chemistry / Q000378:metabolism*; D005798:Genes, Bacterial; D008055:Lipids / Q000096:biosynthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009097:Multienzyme Complexes / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000378:metabolism*; D010226:Parabens / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014774:Virulence
D000942:Antigens, Bacterial; D004952:Esters; D008055:Lipids; D009097:Multienzyme Complexes; D010226:Parabens; C072681:Mycobacterium tuberculosis antigens; C038193:4-hydroxybenzoic acid