New insights into the biogenesis of the cell envelope of corynebacteria: identification and functional characterization of five new mycoloyltransferase genes in Corynebacterium glutamicum.
FEMS Microbiol Lett
; 224(1): 35-44, 2003 Jul 15.
Article
em En
| MEDLINE
| ID: mdl-12855165
ABSTRACT
Mycolic acids, the major lipid constituents of Corynebacterineae, play an essential role in maintaining the integrity of the bacterial cell envelope. We have previously characterized a corynebacterial mycoloyltransferase (PS1) homologous in its N-terminal part to the three known mycobacterial mycoloyltransferases, the so-called fibronectin-binding proteins A, B and C. The genomes of Corynebacterium glutamicum (ATCC13032 and CGL2005) and Corynebacterium diphtheriae were explored for the occurrence of other putative corynebacterial mycoloyltransferase-encoding genes (cmyt). In addition to csp1 (renamed cmytA), five new cmyt genes (cmytB-F) were identified in the two strains of C. glutamicum and three cmyt genes in C. diphtheriae. In silico analysis showed that each of the putative cMyts contains the esterase domain, including the three key amino acids necessary for the catalysis. In C. glutamicum CGL2005 cmytE is a pseudogene. The four new cmyt genes were disrupted in this strain and overexpressed in the inactivated strains. Quantitative analyses of the mycolate content of all these mutants demonstrated that each of the new cMyt-defective strains, except cMytC, accumulated trehalose monocorynomycolate and exhibited a lower content of covalently bound corynomycolate than did the parent strain. For each mutant, the mycolate content was fully restored by complementation with the corresponding wild-type gene. Finally, complementation of the cmytA-inactivated mutant by the individual new cmyt genes established the existence of two classes of mycoloyltransferases in corynebacteria.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aciltransferases
/
Parede Celular
/
Adesinas Bacterianas
/
Corynebacterium
/
Ácidos Micólicos
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
FEMS Microbiol Lett
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
França