H. Ludwig et J. Stulke, The Bacillus subtilis catabolite control protein CcpA exerts all its regulatory functions by DNA-binding, FEMS MICROB, 203(1), 2001, pp. 125-129
In Bacillus subtilis, carbon catabolite control is mediated by the regulato
ry protein CcpA. In addition to loss of catabolite repression, ccpA mutants
exhibit a severe growth defect. They are not able to grow with glucose and
ammonium as single sources of carbon and nitrogen, respectively. Only ccpA
mutant strains carrying either secondary suppressor mutations or that are
affected in specific amino acids in the DNA-binding domain of CcpA grow on
minimal media. We addressed the importance of DNA-binding by CcpA for both
carbon catabolite repression and growth of a mutant strain. A strain specif
ically deleted for the N-terminal DNA-binding domain of CcpA was constructe
d. This deletion resulted in complete loss of catabolite repression of beta
-xylosidase synthesis and prevented bacteria from growing on minimal media
, suggesting that DNA-binding by CcpA is required for both carbon catabolit
e repression and efficient growth on minimal media. (C) 2001 Federation of
European Microbiological Societies. Published by Elsevier Science B.V. All
rights reserved.