A COMPLEX 4-GENE OPERON CONTAINING ESSENTIAL CELL-DIVISION GENE PBPB IN BACILLUS-SUBTILIS

We have cloned and sequenced the promoter-proximal region of the Bacil lus subtilis operon containing the pbp8 gene, encoding essential penic illin-binding protein PBP2B, The first two genes in the operon, design ated yllB and yllC, are significantly similar to genes of unknown func tion similarly positioned upstream of pbpB in Escherichia coli. Bath B . subtilis genes are shown to be nonessential, The third B. subtilis g ene, yllD, is essential, as is the correspondingly positioned ftsL gen e of E. coli. The predicted product of yllD is similar to FtsL in size and distribution of charged residues but is not significantly related in primary amino acid sequence. The major promoter for the cluster li es upstream of the first gene, yllB, but at least one minor promoter l ies within the yllC gene, The operon is transcribed throughout growth at a low level.