Biochemical characterization of a molecular switch involving the heat shock protein ClpC, which controls the activity of ComK, the competence transcription factor of Bacillus subtilis.
Development of genetic competence in Bacillus subtilis is controlled by the competence-specific transcription factor ComK. ComK activates transcription of itself and several other genes required for competence. The activity of ComK is controlled by other genes including mecA, clpC, and comS. We have used purified ComK, MecA, ClpC, and synthetic ComS to study their interactions and have demonstrated the following mechanism for ComK regulation. ClpC, in the presence of ATP, forms a ternary complex with MecA and ComK, which prevents ComK from binding to its specific DNA target. This complex dissociates when ComS is added, liberating active ComK. ClpC and MecA function as a molecular switch, in which MecA confers molecular recognition, connecting ClpC to ComK and to ComS.
Turgay
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Public Health Research Institute, New York, New York 10016, USA.
Hamoen
L W
LW
Venema
G
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Dubnau
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D
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D015153:Blotting, Western; D005798:Genes, Bacterial / Q000235:genetics; D006360:Heat-Shock Proteins / Q000378:metabolism*; D008954:Models, Biological; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology
D001426:Bacterial Proteins; C087481:ClpC protein, Bacteria; C093539:ComS protein, Bacillus subtilis; D006360:Heat-Shock Proteins; D014157:Transcription Factors; C083616:mecA protein, Bacillus subtilis; C087449:comK protein, Bacillus subtilis; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases