Open AccessEnhanced Heterologous Production of Desosaminyl Macrolides and Their Hydroxylated Derivatives by Overexpression of the pikD Regulatory Gene in Streptomyces venezuelae
Author(s) -
Won Seok Jung,
SeJin Jeong,
Sung Ryeol Park,
Cha Yong Choi,
Byoung Chul Park,
Je Won Park,
Yeo Joon Yoon
Publication year - 2008
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02296-07
Subject(s) - heterologous , streptomyces , streptomycetaceae , gene , biology , actinomycetales , regulator gene , microbiology and biotechnology , biochemistry , chemistry , bacteria , genetics , regulation of gene expression
To elevate the production level of heterologous polyketide inStreptomyces venezuelae , an additional copy of the positive regulatory genepikD was introduced into the pikromycin (Pik) polyketide synthase (PKS) deletion mutant ofS. venezuelae ATCC 15439 expressing tylosin PKS genes. The resulting mutant strain showed enhanced production of both tylactone (TL) and desosaminyl tylactone (DesTL) of 2.7- and 17.1-fold, respectively. The notable increase in DesTL production strongly suggested that PikD upregulates the expression of the desosamine (des ) biosynthetic gene cluster. In addition, two hydroxylated forms of DesTL were newly detected from the extract of this mutant. These hydroxylated forms presumably resulted from a PikD-dependent increase in expression of thepikC gene that encodes P450 hydroxylase. Gene expression analysis by reverse transcriptase PCR and bioconversion experiments of 10-deoxymethynolide, narbonolide, and TL into the corresponding desosaminyl macrolides indicated that PikD is a positive regulator of thedes andpikC genes, as well as the Pik PKS genes. These results demonstrate the role of PikD as a pathway-specific positive regulator of the entire Pik biosynthetic pathway and its usefulness in the development of a host-vector system for efficient heterologous production of desosaminyl macrolides and novel hydroxylated compounds.