TY - JOUR
T1 - Bacillus subtilis σB is regulated by a binding protein (RsbW) that blocks its association with core RNA polymerase
AU - Benson, Andrew K.
AU - Haldenwang, William G.
PY - 1993/3/15
Y1 - 1993/3/15
N2 - σB is a secondary σ factor of Bacillus subtilis. RNA polymerase containing σB transcribes a subset of genes that are expressed after heat shock or the onset of the stationary phase of growth. Three genes (rsbV, rsbW, and rsbX), cotranscribed with the σB structural gene (sigB), regulate σB-dependent gene expression. RsbW is the primary inhibitor of this system with the other gene products acting upstream of RsbW in the σB regulatory pathway. Evidence is now presented that RsbW inhibits σB-dependent transcription by binding to σB and blocking the formation of a σB-containing RNA polymerase holoenzyme. Antibodies specific for either RsbW or σB will coprecipitate both proteins from crude cell extracts. This is not due to the presence of both proteins on RNA polymerase. Western blot analysis of B. subtilis extracts that had been fractionated by gel-filtration chromatography revealed a single peak of RsbW that did not coelute with RNA polymerase and two peaks of σB protein: one that eluted with RNA polymerase and a second that overlapped the fractions that contained RsbW. Reconstitution experiments were performed in which partially purified σB and RsbW were added to core RNA polymerase and tested for their ability to influence the transcription of a σB-dependent promoter (etc) in vitro. RsbW efficiently blocked σB-dependent transcription but only if it was incubated with σB prior to the addition of the core enzyme.
AB - σB is a secondary σ factor of Bacillus subtilis. RNA polymerase containing σB transcribes a subset of genes that are expressed after heat shock or the onset of the stationary phase of growth. Three genes (rsbV, rsbW, and rsbX), cotranscribed with the σB structural gene (sigB), regulate σB-dependent gene expression. RsbW is the primary inhibitor of this system with the other gene products acting upstream of RsbW in the σB regulatory pathway. Evidence is now presented that RsbW inhibits σB-dependent transcription by binding to σB and blocking the formation of a σB-containing RNA polymerase holoenzyme. Antibodies specific for either RsbW or σB will coprecipitate both proteins from crude cell extracts. This is not due to the presence of both proteins on RNA polymerase. Western blot analysis of B. subtilis extracts that had been fractionated by gel-filtration chromatography revealed a single peak of RsbW that did not coelute with RNA polymerase and two peaks of σB protein: one that eluted with RNA polymerase and a second that overlapped the fractions that contained RsbW. Reconstitution experiments were performed in which partially purified σB and RsbW were added to core RNA polymerase and tested for their ability to influence the transcription of a σB-dependent promoter (etc) in vitro. RsbW efficiently blocked σB-dependent transcription but only if it was incubated with σB prior to the addition of the core enzyme.
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U2 - 10.1073/pnas.90.6.2330
DO - 10.1073/pnas.90.6.2330
M3 - Article
C2 - 8460143
AN - SCOPUS:0027401048
SN - 0027-8424
VL - 90
SP - 2330
EP - 2334
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 6
ER -