Organization of the biosynthetic gene cluster for the polyketide anthelmintic macrolide avermectin in Streptomyces avermitilis.

ABSTRACT: Analysis of the gene cluster from Streptomyces avermitilis that governs the biosynthesis of the polyketide anthelmintic avermectin revealed that it contains four large ORFs encoding giant multifunctional polypeptides of the avermectin polyketide synthase (AVES 1, AVES 2, AVES 3, and AVES 4). These clustered polyketide synthase genes responsible for avermectin biosynthesis together encode 12 homologous sets of enzyme activities (modules), each catalyzing a specific round of polyketide chain elongation. The clustered genes encoding polyketide synthase are organized as two sets of six modular repeats, aveA1-aveA2 and aveA3-aveA4, which are convergently transcribed. The total of 55 constituent active sites makes this the most complex multifunctional enzyme system identified to date. The sequen

SUBMITTER: Ikeda H 

PROVIDER: S-EPMC22239 | biostudies-literature | 1999 Aug

REPOSITORIES: biostudies-literature