title: CcpA mutants with differential activities in Bacillus subtilis.
abstract: CcpA is the master regulator for carbon catabolite regulation in Bacillus subtilis and regulates more than 300 genes by repression or activation. To revealthe effects of different functional domains of CcpA on various regulatory modes, we compared the activities of CcpA point mutants in activation (alsS, ackA) and repression (xynP, gntR). CcpA variants mutated at residues in the HPrSerP-binding region without allosteric functions are inactive. On the other hand, CcpA variants mutated at residues that change their conformation upon HPrSerP or CrhP binding regulate only ackA. Another set of mutants with alterations in the corepressor-binding region show glucose-independent regulation of xynP. The data presented here demonstrate the involvement of HPrSerP and/or CrhP in activation of ackA and alsS by CcpA. Furthermore, these data also indicate that activation and repression mediated by CcpA may utilize different conformational changes of the protein.
authors.affiliation: Lehrstuhl fur Mikrobiologie, Institut fur Biologie, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Germany.
authors.forename: Mareen
authors.initials: M
authors.lastname: Sprehe
authors.forename: Gerald
authors.initials: G
authors.lastname: Seidel
authors.forename: Marco
authors.initials: M
authors.lastname: Diel
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hillen
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C069286:catabolite control proteins, bacteria