Molecular evolution of aromatic polyketides and comparative sequence analysis of polyketide ketosynthase and 16S ribosomal DNA genes from various streptomyces species.

ABSTRACT: A 613-bp fragment of an essential ketosynthase gene from the biosynthetic pathway of aromatic polyketide antibiotics was sequenced from 99 actinomycetes isolated from soil. Phylogenetic analysis showed that the isolates clustered into clades that correspond to the various classes of aromatic polyketides. Additionally, sequencing of a 120-bp fragment from the gamma-variable region of 16S ribosomal DNA (rDNA) and subsequent comparative sequence analysis revealed incongruity between the ketosynthase and 16S rDNA phylogenetic trees, which strongly suggests that there has been horizontal transfer of aromatic polyketide biosynthesis genes. The results show that the ketosynthase tree could be used for DNA fingerprinting of secondary metabolites and for screening interesting aromatic polyketide bi

SUBMITTER: Metsa-Ketela M 

PROVIDER: S-EPMC124067 | biostudies-literature | 2002 Sep

REPOSITORIES: biostudies-literature