Biochemical Activities of the absA Two-Component System of Streptomyces coelicolor

AUTOR(ES)

Sheeler, Nancy L.

FONTE

American Society for Microbiology

RESUMO

The AbsA1 sensor kinase and its cognate response regulator AbsA2 are important regulators of antibiotic synthesis in Streptomyces coelicolor. While certain point mutations in absA1 reduce or eliminate the synthesis of several antibiotics, null mutations in these genes bring about enhanced antibiotic synthesis. We show here that AbsA1, which is unusual in sequence and structure, is both an AbsA2 kinase and an AbsA2∼P phosphatase. The half-life of AbsA2∼P in solution is 68.6 min, consistent with a role in maintaining a relatively stable state of transcriptional repression or activation. We find that mutations in the absA locus that enhance antibiotic synthesis impair AbsA2 kinase activity and that mutations that repress antibiotic synthesis impair AbsA2∼P phosphatase activity. These results support a model in which the phosphorylation state of AbsA2 is determined by the balance of the kinase and phosphatase activities of AbsA1 and where AbsA2∼P represses antibiotic biosynthetic genes either directly or indirectly.

Documentos Relacionados

• Regulation of the Streptomyces coelicolor Calcium-Dependent Antibiotic by absA, Encoding a Cluster-Linked Two-Component System
• Transcriptional Regulation of Streptomyces coelicolor Pathway-Specific Antibiotic Regulators by the absA and absB Loci
• A small protein that mediates the activation of a two-component system by another two-component system
• A putative two-component regulatory system involved in secondary metabolism in Streptomyces spp.
• The Pleiotropic Two-Component Regulatory System PhoP-PhoQ†