title: The Brevibacterium flavum sigma factor SigB has a role in the environmental stress response.
abstract: We have previously cloned a gene encoding a SigB, a principal-like sigma factor in Brevibacterium flavum, which was induced by several stress conditions. To clarify the in vivo function of this sigma factor, the sigB gene was disrupted by a homologous recombination, replacing the internal essential coding region in B. flavum chromosome by a kanamycin resistance marker gene. This mutation dramatically decreased vegetative growth rates of B. flavum. Studies of the effect of the sigB mutation on growth and viability of the cells under conditions of stress showed that the sigB mutant had increased susceptibility to acid, salt, alcohol, heat and cold stress. The plasmid-born wild-type sigB gene complemented the mutation. Based on the results, we propose that SigB has a role in vegetative growth and in response to various environmental stresses.
authors.affiliation: Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
authors.forename: Nora
authors.initials: N
authors.lastname: Halgasova
authors.forename: Gabriela
authors.initials: G
authors.lastname: Bukovska
authors.forename: Jana
authors.initials: J
authors.lastname: Ugorcakova
authors.forename: Jozef
authors.initials: J
authors.lastname: Timko
authors.forename: Jan
authors.initials: J
authors.lastname: Kormanec
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D040142:Brevibacterium flavum / Q000254:growth & development / Q000502:physiology*; D017353:Gene Deletion; D006360:Heat-Shock Proteins / Q000235:genetics / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; C079011:SigB protein, Bacteria; D012808:Sigma Factor