Summary: The nucleotide sequence of wprA, a protease-encoding gene of Bacillus subtilis 168, is reported. The gene, expressed during the exponential growth phase, belongs to a monocistronic operon. WprA is a 96 kDa polypeptide endowed with a signal peptide, as well as a propeptide. Upon processing and export, it gives rise to two previously identified cell-wall-bound proteins, CWBP23 and 52. Processing of WprA exhibits a novel feature of protein export, whereby removal of the middle part of the molecule accompanies the targeting to the cell wall of its N- and C-terminal parts, which correspond to CWBP23 and 52, respectively. Sequence analyses and enzymic assays reveal that CWBP52 is a serine protease. Growth rate, cell morphology, sporulation and motility of wprA mutants apparently do not differ from those of the parent strain.