title: RegG, a CcpA homolog, participates in regulation of amylase-binding protein A gene (abpA) expression in Streptococcus gordonii.
abstract: The amylase-binding protein A (AbpA) of Streptococcus gordonii was found to be undetectable in supernatants of mid-log-phase cultures containing >1% glucose but abundant in supernatants of cultures made with brain heart infusion (BHI), which contains 0.2% glucose. A 10-fold decrease in the level of abpA mRNA in S. gordonii cells cultured in BHI was noted after the addition of glucose to 1%. Analysis of the abpA sequence revealed a potential catabolite responsive element CRE 153 bp downstream of the putative translational start site. A catabolite control protein A gene (ccpA) homolog from S. gordonii, designated regG, was cloned. A regG mutant strain demonstrated moderately less repression of abpA transcription in the presence of 1% glucose. Diauxic growth with glucose and lactose was not affected in the RegG mutant compared to the wild-type parental strain. These results suggest that while RegG plays a role in abpA expression, other mechanisms of catabolite repression are present.
authors.affiliation: Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Rogers
authors.forename: F A
authors.initials: FA
authors.lastname: Scannapieco
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013291:Streptococcus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C112818:AbpA protein, Streptococcus gordonii; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D003470:Culture Media; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C069286:catabolite control proteins, bacteria