Characterization of proteins belonging to the CHAP-related superfamily within the Firmicutes.
Cell division is a dynamic process ending by separation of the daughter cells. This final step requires the cleavage of the murein septum synthetized during cell division. In Streptococcus thermophilus, cse plays an important role in cell separation. Cse protein contains, at its N-terminal end, a signal peptide and a putative LysM motif suggesting that it is secreted and able to bind to the cell wall. Furthermore, the C-terminus of Cse carries a putative cysteine, histidine-dependent amidohydrolases/peptidases (CHAP) domain conferring to the protein a potential catalytic activity. To gain insight into the role of Cse in the cell division process, in silico analysis of the Firmicutes proteins displaying CHAP-related domain was undertaken. This work allowed us to distinguish and characterize within the Firmicutes the 2 families of proteins (CHAP and NlpC/p60) belonging to the CHAP superfamily. These 2 families regroup mainly peptidoglycan hydrolases. Data from the literature indicate that NlpC/p60 and CHAP proteins cleave distinct peptidoglycan bonds. Among the enzymes characterized within the Firmicutes, NlpC/p60 proteins are gamma-D-glutamate-meso-diaminopimelate muropeptidase. Instead, CHAP enzymes involved in cell separation are N-acetylmuramoyl-L-alanine amidase and CHAP lysins have endopeptidase activity.
Layec
Séverine
S
Laboratoire de Génétique et Microbiologie, UMR INRA 1128, IFR 110, Faculté des Sciences et Techniques, Université Henri Poincaré Nancy 1, Vandoeuvre-lès-Nancy, France.
Decaris
Bernard
B
Leblond-Bourget
Nathalie
N
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002455:Cell Division; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000166:cytology* / Q000201:enzymology*; D008969:Molecular Sequence Data; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D048249:Streptococcus thermophilus / Q000166:cytology / Q000201:enzymology
D001426:Bacterial Proteins; D010450:Endopeptidases; C019404:gamma-D-glutamyl-meso-diaminopimelate peptidase I; D009238:N-Acetylmuramoyl-L-alanine Amidase