Bacillus cereus strain SE-1: nucleotide sequence of the sphingomyelinase C gene.

The genes encoding two different phospholipase C exoenzymes of Bacillus cereus are directly linked. A sequence comprising the gene for phospholipase C and part of the sphingomyelinase C (SMase) gene from strain SE-1 (1) as well as the entire SMase gene sequence from strain IAM 1208 (2) have recently been determined. We now report the complete sequence of the SMase gene from strain SE-1. Surprisingly, 27 amino acid (aa) changes were found when the derived aa sequences of the SMase genes of the two strains were compared. The nucleotide sequences of the SMase coding regions differ by 9.9%. The aa changes are indicated in the figure with the corresponding aa of the IAM 1208 SMase shown above the SE-1 sequence. The putative SD sequences of the SMase gene and a possible downstream gene (start codon boxed) are underlined. The vertical arrow indicates the junction between the putative signal peptide and the mature exoenzyme (2). A possible Rho-independent terminator is indicated by horizontal arrows above the sequence. The DNA sequence is numbered to match the previouly published sequence (1) and the database entry.