Osmoregulation inStreptomyces coelicolor: modulation of SigB activity by OsaC

Martínez, Lorena Fernández, Bishop, Amy, Parkes, Lindsay, Del Sol, Ricardo, Salerno, Paola, Sevcikova, Beatrica, Mazurakova, Vladislava, Kormanec, January and Dyson, Paul (2009) Osmoregulation inStreptomyces coelicolor: modulation of SigB activity by OsaC. Molecular Microbiology, 71 (5). pp. 1250-1262. ISSN 0950382X DOI https://doi.org/10.1111/j.1365-2958.2009.06599.x

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As free-living non-motile saprophytes, Streptomyces need to adapt to a wide range of environmental conditions and this is reflected by an enormous diversity of regulatory proteins encoded by, for example, the genome of the model streptomycete Streptomyces coelicolor. In this organism, we have identified a new osmoregulation gene, osaC, encoding a member of a novel family of regulatory proteins. Members of the family have a predicted domain composition consisting of an N-terminal kinase domain related to anti-sigma factors, sensory Pas and Gaf domains, and a C-terminal phosphatase domain. osaC is linked to the response regulator gene osaB; expression analysis of the latter revealed that it is induced after osmotic stress in a σB-dependent manner. OsaC is required to return osaB and sigB expression back to constitutive levels after osmotic stress. From analysis of the activities of OsaCΔPho, lacking the C-terminal phosphatase domain, and OsaCN92A, with a substitution of a critical asparagine residue in the kinase domain, we infer that this N-terminal domain functions as a σB anti-sigma factor. Indeed, co-purification experiments indicate association of OsaC and σB. These results support a model for post-osmotic stress modulation of σB activity by OsaC.

Item Type: Article
Subjects: Q Science > QH Natural history > QH301 Biology
Q Science > QH Natural history > QH426 Genetics
Date Deposited: 19 Apr 2016 14:50
URI: http://repository.edgehill.ac.uk/id/eprint/7289

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