Enhanced Heterologous Production of Desosaminyl Macrolides and Their Hydroxylated Derivatives by Overexpression of the pikD Regulatory Gene in Streptomyces venezuelae

Abstract

To elevate the production level of heterologous polyketide in Streptomyces venezuelae, an additional copy of the positive regulatory gene pikD was introduced into the pikromycin (Pik) polyketide synthase (PKS) deletion mutant of S. 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 PikDdependent increase in expression of the pikC 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 the des and pikC 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.

Roles of fkbN in Positive Regulation and tcs7 in Negative Regulation of FK506 Biosynthesis in Streptomyces sp. Strain KCTC 11604BP

“…Furthermore, a LAL family regulator, FkbN, in the FK506 biosynthetic cluster of Streptomyces sp. KCTC 11604BP, probably caused the increased expression of FK506 biosynthetic genes, as reported for other LAL family regulators (13,14).…”

“…Total RNA was isolated from the wild-type and mutant strains of Streptomyces sp. KCTC 11604BP, which had been grown in liquid R2YE medium with or without apramycin, as described previously (14). The RNA preparations were treated with DNase I (Qiagen) to eliminate possible chromosomal DNA contamination.…”

Development of a Streptomyces venezuelae-Based Combinatorial Biosynthetic System for the Production of Glycosylated Derivatives of Doxorubicin and Its Biosynthetic Intermediates

“…Furthermore, 17 unnatural glycosylated derivatives of doxorubicin or its biosynthetic intermediates were generated (Fig. 2), demonstrating the potential of this S. venezuelae system for engineered generation of doxorubicin analogs with modified sugar moieties as well as other polyketides glycosylated with unnatural sugars (10,(13)(14)(15).…”

“…The pikromycin-producing Streptomyces venezuelae ATCC 15439 has been developed as a favorable host for combinatorial biosynthesis and heterologous expression of natural product biosynthetic pathways originating in other organisms due to its fast growth and relative ease of genetic manipulation (10,(13)(14)(15)(33)(34)(35). In the present study, an S. venezuelae-based combinatorial biosynthetic system was constructed to convert exogenously fed doxorubicin aglycone ε-rhodomycinone (ε-RHO) into glycosylated doxorubicin analogs.…”

Enhanced rapamycin production in Streptomyces hygroscopicus by integrative expression of aveR, a LAL family transcriptional regulator

“…However, low rapamycin productivity is a problem, and a massive amount of research has been dedicated to enhancing rapamycin production from cultured bacteria (Kuscer et al 2007;Park et al 2010). Genetic manipulation of bacteria, such as increasing the copy number of regulators, is the most common technique, which results in an enhanced yield (Jung et al 2008;Jnawali et al 2010;Hung et al 2006).…”