title: Catabolite repression in Lactobacillus casei ATCC 393 is mediated by CcpA.
abstract: The chromosomal ccpA gene from Lactobacillus casei ATCC 393 has been cloned and sequenced. It encodes the CcpA protein, a central catabolite regulator belonging to the LacI-GalR family of bacterial repressors, and shows 54% identity with CcpA proteins from Bacillus subtilis and Bacillus megaterium. The L. casei ccpA gene was able to complement a B. subtilis ccpA mutant. An L. casei ccpA mutant showed increased doubling times and a relief of the catabolite repression of some enzymatic activities, such as N-acetylglucosaminidase and phospho-beta-galactosidase. Detailed analysis of CcpA activity was performed by using the promoter region of the L. casei chromosomal lacTEGF operon which is subject to catabolite repression and contains a catabolite responsive element (cre) consensus sequence. Deletion of this cre site or the presence of the ccpA mutation abolished the catabolite repression of a lacp::gusA fusion. These data support the role of CcpA as a common regulatory element mediating catabolite repression in low-GC-content gram-positive bacteria.
authors.affiliation: Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Burjassot, Valencia, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Monedero
authors.forename: M J
authors.initials: MJ
authors.lastname: Gosalbes
authors.forename: G
authors.initials: G
authors.lastname: Pérez-Martínez
mesh_terms: D000118:Acetylglucosaminidase / Q000096:biosynthesis; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D004794:Enzyme Repression; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005816:Genetic Complementation Test; D006026:Glycoside Hydrolases; D006094:Gram-Positive Bacteria / Q000235:genetics; D007763:Lac Operon / Q000235:genetics; D007780:Lacticaseibacillus casei / Q000235:genetics*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012097:Repressor Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C069286:catabolite control proteins, bacteria; D006026:Glycoside Hydrolases; D001616:beta-Galactosidase; D000118:Acetylglucosaminidase; C022361:6-phospho-beta-galactosidase