THE PBP-5 SYNTHESIS REPRESSOR (PSR) GENE OF ENTEROCOCCUS-HIRAE ATCC-9790 IS SUBSTANTIALLY LONGER THAN PREVIOUSLY REPORTED

A reexamination of the nucleotide sequence of the psr gene of Enteroco ccus hirae revealed the presence of two additional nucleotides at resi dues 1190 and 1191. As a result, instead of a stop codon after 148 aa, the psr gene product would contain 293 aa residues. The revised size of the gene product was confirmed by subsequently cloning and expressi ng the psr gene in Escherichia coli. The derived amino acid sequence o f the revised psr gene product was found to be similar to several othe r proteins in the combined GenBank/EMBL database. The protein products of some of these genes are thought to play regulatory role(s) in exo or capsular polysaccharide synthesis and/or in cell wall metabolism. A ll the putative homologs of the revised Psr appear to have a putative membrane-anchoring domain at their N-termini. Amino acid blocks with h igh degrees of similarity have been identified in the aligned sequence s, and it is suggested that these common motifs could be of structural or functional importance. (C) 1998 Published by Elsevier Science B.V. All rights reserved.