Open AccessIdentification of the Polyketide Synthase Involved in the Biosynthesis of the Surface-Exposed Lipooligosaccharides in Mycobacteria
Author(s) -
Gilles Etienne,
Wladimir Malaga,
Françoise Laval,
Anne Lemassu,
Christophe Guilhot,
Mamadou Daffé
Publication year - 2009
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.01235-08
Subject(s) - biology , mycobacterium marinum , glycolipid , complementation , polyketide synthase , mycobacterium smegmatis , mutant , biochemistry , microbiology and biotechnology , biosynthesis , polyketide , mycolic acid , mycobacterium , gene , mycobacterium tuberculosis , bacteria , genetics , tuberculosis , medicine , pathology
Lipooligosaccharides (LOS) are highly antigenic glycolipids produced by a number ofMycobacterium species, which include “M. canettii ,” a member of theM. tuberculosis complex, and the opportunistic pathogensM. marinum andM. kansasii . The various LOS share a core composed of trehalose esterified by at least 1 mole of polymethyl-branched fatty acid (PMB-FA) and differ from one another by their oligosaccharide extensions. In this study, we identified a cluster of genes, MSMEG_4727 through MSMEG_4741, likely involved in the synthesis of LOS inM. smegmatis . Disruption of MSMEG_4727 (the ortholog ofpks5 ofM. tuberculosis ), which encodes a putative polyketide synthase, resulted in the concomitant abrogation of the production of both PMB-FA and LOS in the mutant strain. Complementation of the mutant with the wild-type gene fully restored the phenotype. We also showed that, in contrast to the case for “M. canettii ” andM. marinum , LOS are located in deeper compartments of the cell envelope ofM. smegmatis . The availability of two mycobacterial strains differing only in LOS production should help in defining the biological role(s) of this important glycolipid.