IDENTIFICATION OF 2 GENES, CPSX AND CPSY WITH PUTATIVE REGULATORY FUNCTION ON CAPSULE EXPRESSION IN GROUP-B STREPTOCOCCI

Two divergently transcribed open reading frames: cpsX and cpsY separat ed by a common regulatory region was identified upstream of the cpsA-D genes involved in polysaccharide capsule biosynthesis in group B stre ptococci (GBS). We suggest that these genes are involved in the regula tion of capsule expression in GBS, since the CpsX protein shares seque nce similarities with LytR of Bacillus subtilis, an attenuator of tran scription while CpsY has similarity to a wide variety of members of th e LysR family of transcriptional regulators. No deletions, insertions, DNA rearrangements, or apparent differences were discovered in the po stulated regulatory genes when the gene region was compared in GBS wit h different capsule phenotypes, Thus, other yet unidentified gene loci may control capsule phase variation in GBS. (C) 1998 Federation of Eu ropean Microbiological Societies. Published by Elsevier Science B.V. A ll rights reserved.