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Bacillus licheniformis sigB operon encoding the general stress transcription factor σB

1998; Elsevier BV; Volume: 212; Issue: 1 Linguagem: Inglês

10.1016/s0378-1119(98)00140-1

1879-0038

Margaret S. Brody, Chester W. Price,

Bacterial biofilms and quorum sensing

The general stress response of the Gram-positive soil bacterium Bacillus subtilis is controlled by the σB transcription factor. σB activity is regulated by the newly discovered partner switching mechanism of signal transduction, which integrates the two different classes of challenges which posttranslationally activate σB: environmental stress and energy stress. Our investigation of a possible σB homologue in the related soil bacterium B. licheniformis had two goals. First, this study would contribute to understanding the distribution of the σB general stress system among Gram-positive bacteria. Second, a phylogenetic comparison of regulatory systems can supplement genetic and biochemical analysis by revealing conserved features that are critical for function. We report here that (1) B. licheniformis cells contain a protein that closely resembles B. subtilis σB in size and antigenic properties; (2) the level of this potential σB homologue rapidly increases following environmental or energy stress; and (3) the B. licheniformis genome encodes a homologue of the sigB general stress operon, including the σB structural gene and seven rsb regulatory genes. Based on these results, B. licheniformis possesses a general stress system likely regulated by two coupled partner switching modules that sense and integrate the two broad classes of activating stress signals.