Screening and identification of macrolide cytochrome P-450 hydroxylase gene from streptomycetes isolated in Thailand

Abstract

Streptomyces is a gram positive filamentous bacteria that produce pharmaceutically important metabolites (macrolide) including antimicrobial and antitumor. Macrolide cytochrome P-450 hydroxylase catalyzes the hydroxylation reaction of macrolide lead compound in the tailoring step of the macrolide biosynthesis. We attempted to screen and identify macrolide cytochrome P-450 hydroxylase gene from Streptomyces spp. isolated in Thailand. Twenty genomic DNA isolated from Streptomyces isolates existing the macrolide P-450 genes were determined by dot blot hybridization using picK P-450 hydroxylase gene probe. Fourteen macrolide P-450 genes from twenty positively hybridized genomic DNA samples were amplified by polymerase chain reaction (PCR). The PCR products containing putative macrolide P-450 of Streptomyces strains SMC 48, SMC 59 and SMC 78 were cloned and sequenced. Sequence analyses of their nucleotide and deduced amino acid sequences showed high homology to members of the P-450 genes which catalyze hydroxylation of macrolide lead compound. The phylogenetic analysis demonstrated that the putative macrolide P-450 genes of our isolates have evolutionary relationships to the P-450s of the same bacterial origin,streptomyces.