Expression of the chaplin and rodlin hydrophobic sheath proteins in Streptomyces venezuelae is controlled by σBldN and a cognate anti-sigma factor, RsbN

Authors

  • Maureen J. Bibb,

    Corresponding author
    1. Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
    Search for more papers by this author
  • Ágota Domonkos,

    1. Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
    Search for more papers by this author
    • Present address: Agricultural Biotechnology Center, Szent-Györgyi Albert u. 4, Gödöllő, Hungary.

  • Govind Chandra,

    1. Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
    Search for more papers by this author
  • Mark J. Buttner

    1. Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
    Search for more papers by this author

Summary

The chaplin and rodlin proteins together constitute the major components of the hydrophobic sheath that coats the aerial hyphae and spores in Streptomyces, and mutants lacking the chaplins are unable to erect aerial hyphae and differentiate on minimal media. We have gained insight into the developmental regulation of the chaplin (chp) and rodlin (rdl) genes by exploiting a new model species, Streptomyces venezuelae, which sporulates in liquid culture. Using microarrays, the chaplin and rodlin genes were found to be highly induced during submerged sporulation in a bldN-dependent manner. Using σBldN ChIP-chip, we show that this dependence arises because the chaplin and rodlin genes are direct biochemical targets of σBldN. sven3186 (here named rsbN for regulator of sigma BldN), the gene lying immediately downstream of bldN, was also identified as a target of σBldN. Disruption of rsbN causes precocious sporulation and biochemical experiments demonstrate that RsbN functions as a σBldN-specific anti-sigma factor.

Ancillary