Involvement of two putative alternative sigma factors in stress response of the radioresistant bacterium Deinococcus radiodurans.

ABSTRACT: Two genes bearing similarity to alternative sigma factors were identified in the Deinococcus radiodurans genome sequence and designated sig1 and sig2. These genes were cloned and inactivated, and both were found to be important for survival during heat and ethanol stress, although the sig1 mutants displayed a more severe phenotype than the sig2 mutants. Reporter gene fusions to the groESL and dnaKJ operons transformed into these mutant backgrounds indicated that sig1 is required for the heat shock induction of groESL and dnaKJ, whereas sig2 mutants show a more moderate defect in dnaKJ induction and are not impaired for groESL induction. Essentiality tests suggested that neither sig1 nor sig2 is essential under all conditions. Sequence comparisons demonstrated that the sig1 gene product is

SUBMITTER: Schmid AK 

PROVIDER: S-EPMC151957 | biostudies-literature | 2002 Nov

REPOSITORIES: biostudies-literature