Characterization of dacC , Which Encodes a New Low-Molecular-Weight Penicillin-Binding Protein in Bacillus subtilis

Abstract

ABSTRACT The pbp gene (renamed dacC ), identified by the Bacillus subtilis genome sequencing project, encodes a putative 491-residue protein with sequence homology to low-molecular-weight penicillin-binding proteins. Use of a transcriptional dacC-lacZ fusion revealed that dacC expression (i) is initiated at the end of stationary phase; (ii) depends strongly on transcription factor ς H ; and (iii) appears to be initiated from a promoter located immediately upstream of yoxA , a gene of unknown function located upstream of dacC on the B. subtilis chromosome. A B. subtilis dacC insertional mutant grew and sporulated identically to wild-type cells, and dacC and wild-type spores had the same heat resistance, cortex structure, and germination and outgrowth kinetics. Expression of dacC in Escherichia coli showed that this gene encodes an ∼59-kDa membrane-associated penicillin-binding protein which is highly toxic when overexpressed.