title: The ClgR protein regulates transcription of the clpP operon in Bifidobacterium breve UCC 2003.
abstract: Five clp genes (clpC, clpB, clpP1, clpP2, and clpX), representing chaperone- and protease-encoding genes, were previously identified in Bifidobacterium breve UCC 2003. In the present study, we characterize the B. breve UCC 2003 clpP locus, which consists of two paralogous genes, designated clpP1 and clpP2, whose deduced protein products display significant similarity to characterized ClpP peptidases. Transcriptional analyses showed that the clpP1 and clpP2 genes are transcribed in response to moderate heat shock as a bicistronic unit with a single promoter. The role of a clgR homologue, known to control the regulation of clpP gene expression in Streptomyces lividans and Corynebacterium glutamicum, was investigated by gel mobility shift assays and DNase I footprint experiments. We show that ClgR, which in its purified form appears to exist as a dimer, requires a proteinaceous cofactor to assist in specific binding to a 30-bp region of the clpP promoter region. In pull-down experiments, a 56-kDa protein copurified with ClgR, providing evidence that the two proteins also interact in vivo and that the copurified protein represents the cofactor required for ClgR activity. The prediction of the ClgR three-dimensional structure provides further insights into the binding mode of this protein to the clpP1 promoter region and highlights the key amino acid residues believed to be involved in the protein-DNA interaction.
authors.affiliation: Department of Genetics, Evolution and Anthropology, University of Parma, Parma, Italy. marco.ventura@unipr.it
authors.forename: Marco
authors.initials: M
authors.lastname: Ventura
authors.forename: Ziding
authors.initials: Z
authors.lastname: Zhang
authors.forename: Michelle
authors.initials: M
authors.lastname: Cronin
authors.forename: Carlos
authors.initials: C
authors.lastname: Canchaya
authors.forename: John G
authors.initials: JG
authors.lastname: Kenny
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Fitzgerald
authors.forename: Douwe
authors.initials: D
authors.lastname: van Sinderen
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology*; D001483:Base Sequence; D001644:Bifidobacterium / Q000235:genetics* / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000235:genetics; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D006358:Hot Temperature; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009876:Operon; D010447:Peptide Hydrolases / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012329:RNA, Bacterial; D012333:RNA, Messenger / Q000032:analysis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D048170:Streptomyces lividans / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D010447:Peptide Hydrolases