Identification of two genes, cpsX and cpsY, with putative regulatory function on capsule expression in group B streptococci.
Two divergently transcribed open reading frames: cpsX and cpsY separated by a common regulatory region was identified upstream of the cpsA-D genes involved in polysaccharide capsule biosynthesis in group B streptococci (GBS). We suggest that these genes are involved in the regulation of capsule expression in GBS, since the CpsX protein shares sequence similarities with LytR of Bacillus subtilis, an attenuator of transcription while CpsY has similarity to a wide variety of members of the LysR family of transcriptional regulators. No deletions, insertions, DNA rearrangements, or apparent differences were discovered in the postulated regulatory genes when the gene region was compared in GBS with different capsule phenotypes. Thus, other yet unidentified gene loci may control capsule phase variation in GBS.
Koskiniemi
S
S
Department of Clinical Bacteriology, Umeå University, Sweden.
Sellin
M
M
Norgren
M
M
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics; D016667:Bacterial Capsules / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction / Q000379:methods; D015183:Restriction Mapping; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013292:Streptococcus agalactiae / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D014157:Transcription Factors / Q000235:genetics; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins; C114775:CpsX protein, Streptococcus agalactiae; C114776:CpsY protein, Streptococcus agalactiae; C093500:LytR protein, Staphylococcus aureus; D014157:Transcription Factors; C073470:LysR protein, Bacteria