The polyketide synthase Pks13 catalyzes a novel mechanism of lipid transfer in mycobacteria.
Chem Biol
; 21(12): 1660-9, 2014 Dec 18.
Article
em En
| MEDLINE
| ID: mdl-25467124
ABSTRACT
Mycolate-containing compounds constitute major strategic elements of the protective coat surrounding the tubercle bacillus. We have previously shown that FAAL32-Pks13 polyketide synthase catalyzes the condensation reaction, which produces α-alkyl ß-ketoacids, direct precursors of mycolic acids. In contrast to the current biosynthesis model, we show here that Pks13 catalyzes itself the release of the neosynthesized products and demonstrate that this function is carried by its thioesterase-like domain. Most importantly, in agreement with the prediction of a trehalose-binding pocket in its catalytic site, this domain exhibits an acyltransferase activity and transfers Pks13's products onto an acceptor molecule, mainly trehalose, leading to the formation of the trehalose monomycolate precursor. Thus, this work allows elucidation of the hinge step of the mycolate-containing compound biosynthesis pathway. Above all, it highlights a unique mechanism of transfer of polyketide synthase products in mycobacteria, which is distinct from the conventional intervention of the discrete polyketide-associated protein (Pap)-type acyltransferases.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Policetídeo Sintases
/
Biocatálise
/
Ácidos Micólicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article