Journal Article

A Novel Two-Component System Involved in the Transition to Secondary Metabolism in Streptomyces coelicolor

Gullón, Sonia, Rozas, Daniel, Mellado, Rafael P.

2012

Overview

Bacterial two-component signal transduction regulatory systems are the major set of signalling proteins frequently mediating responses to changes in the environment. They typically consist of a sensor, a membrane-associated histidine kinase and a cytoplasmic response regulator. The membrane-associated sensor detects the environmental signal or stress, whereas the cytoplasmic regulatory protein controls the cellular response usually by gene transcription modulation. METHODOLOGY/PRINCIPALFINDINGS: The Streptomyces coelicolor two genes operon SCO5784-SCO5785 encodes a two-component system, where SCO5784 encodes a histidine-kinase sensor and SCO5785 encodes a response regulator protein. When the expression level of the regulator gene decreases, the antibiotic synthesis and sporulation is delayed temporarily in addition to some ribosomal genes became up regulated, whereas the propagation of the regulatory gene in high copy number results in the earlier synthesis of antibiotics and sporulation, as well as the down regulation of some ribosomal genes and, moreover, in the overproduction of several extracellular proteins. Therefore, this two-component system in S. coelicolor seems to influence various processes characterised by the transition from primary to secondary metabolism, as determined by proteomic and transcriptomic analyses. Propagation of SCO5785 in multicopy enhances the production of antibiotics as well as secretory proteins. In particular, the increase in the expression level of secretory protein encoding genes, either as an artefactual or real effect of the regulator, could be of potential usefulness when using Streptomyces strains as hosts for homologous or heterologous extracellular protein production.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Anti-Bacterial Agents - biosynthesis / Antibiotics / Bacteria / Biology / Blood proteins / Cellular signal transduction / Copy number / Environmental changes / Enzymes / Gene expression / Gene Expression Regulation, Bacterial / Gene regulation / Genes / Genetic aspects / Genomes / Histidine / Histidine kinase / Homology / Kinases / Medicine / Metabolism / Mutation / Operon / Physiological aspects / Propagation / Proteins / Proteomics / Sensors / Signal transduction / Signal Transduction - physiology / Signaling / Sporulation / Streptomyces / Streptomyces coelicolor / Streptomyces coelicolor - metabolism / Synthesis / Transcription / Transcription (Genetics)