SVEN_5003 is a Major Developmental Regulator in Streptomyces venezuelae

Abstract

Many regulatory genes that affect cellular development in Streptomyces, such as the canonical bld genes, have already been identified. However, in this study, we identified sven_5003 in Streptomyces venezuelae as a major new developmental regulatory gene, the deletion of which leads to a bald phenotype, typical of bld mutants, under multiple growth conditions. Our data indicated that disruption of sven_5003 also has a differential impact on the production of the two antibiotics jadomycin and chloramphenicol. Enhanced production of jadomycin but reduced production of chloramphenicol were detected in our sven_5003 mutant strain (S. venezuelae D5003). RNA-Seq analysis indicated that SVEN_5003 impacts expression of hundreds of genes, including genes involved in development, primary and secondary metabolism, and genes of unknown function, a finding confirmed by real-time PCR analysis. Transcriptional analysis indicated that sven_5003 is an auto-regulatory gene, repressing its own expression. Despite the evidence indicating that SVEN_5003 is a regulatory factor, a putative DNA-binding domain was not predicted from its primary amino acid sequence, implying an unknown regulatory mechanism by SVEN_5003. Our findings revealed that SVEN_5003 is a pleiotropic regulator with a critical role in morphological development in S. venezuelae.