Sequence analysis of three Bacillus cereus loci carrying PIcR-regulated genes encoding degradative enzymes and enterotoxin.
PIcR is a pleiotropic regulator of extracellular virulence factors in the opportunistic human pathogen Bacillus cereus and the entomopathogenic Bacillus thuringiensis, and is induced in cells entering stationary phase. Among the genes regulated by PIcR are: pIcA, encoding phosphatidylinositol-specific phospholipase C (PI-PLC); plc, encoding phosphatidylcholine-preferring phospholipase C (PC-PLC); nhe, encoding the non-haemolytic enterotoxin; hbl, encoding haemolytic enterotoxin BL (HBL); and genes specifying a putative S-layer like surface protein and a putative extracellular RNase. By analysing 37.1 kb of DNA sequence surrounding hbl, plcA and plcR, 28 ORFs were predicted. Three novel genes putatively regulated by PlcR and encoding a neutral protease (NprB), a subtilase family serine protease (Sfp) and a putative cell-wall hydrolase (Cwh) were identified. The corresponding sfp and cwh genes were located in the immediate upstream region of plcA and could both be regulated by a putative PlcR-binding site positioned between the inversely transcribed genes. Similarly, nprB was positioned directly upstream and transcribed in the opposite orientation to plcR. Genes surrounding plcA, plcR and hblCDAB that were lacking an upstream PlcR regulatory sequence did not appear to serve functions apparently related to PlcR and did not exhibit a conserved organization in Bacillus subtilis.
Økstad
Ole A
OA
Biotechnology Centre of Oslo and School of Pharmacy, University of Oslo, PO Box 1123, N-0349 Oslo, Norway1.
Gominet
Myriam
M
Unité de Biochimie Microbienne, Centre National de la Recherche Scientifique URA 1300, Institut Pasteur, Paris, France2.
Purnelle
Bénédicte
B
Unité de Biochimie Physiologique, Université Catholique de Louvain, Louvain-la-Neuve, Belgium3.
Rose
Matthias
M
Institut für Mikrobiologie, J. W. Göethe Universität, Frankfurt, Germany4.
Lereclus
Didier
D
Unité de Lutte Biologique, Institut National de la Recherche Agronomique, France5.|Unité de Biochimie Microbienne, Centre National de la Recherche Scientifique URA 1300, Institut Pasteur, Paris, France2.
Kolstø
Anne-Brit
AB
Biotechnology Centre of Oslo and School of Pharmacy, University of Oslo, PO Box 1123, N-0349 Oslo, Norway1.
D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins; D001483:Base Sequence; D010450:Endopeptidases / Q000235:genetics*; D004768:Enterotoxins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator / Q000235:genetics*; D006460:Hemolysin Proteins; D006867:Hydrolases / Q000235:genetics; D008969:Molecular Sequence Data; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics; D010738:Type C Phospholipases / Q000235:genetics
D001426:Bacterial Proteins; D004768:Enterotoxins; D006460:Hemolysin Proteins; C099480:PlcR protein, Bacillus; D015534:Trans-Activators; C083961:hemolysin BL protein, Bacillus; C082662:phosphopantetheinyl transferase; D017855:Transferases (Other Substituted Phosphate Groups); D006867:Hydrolases; D010738:Type C Phospholipases; D054801:Phosphoinositide Phospholipase C; D010450:Endopeptidases; D043265:Phosphatidylinositol Diacylglycerol-Lyase