title: Identification and characterization of a putative endolysin encoded by episomal phage phiSM101 of Clostridium perfringens.
abstract: Clostridium perfringens produces potent toxins and histolytic enzymes, causing various diseases including life-threatening fulminant diseases in humans and other animals. Aiming at utilizing a phage endolysin as a therapeutic alternative to antibiotics, we surveyed the genome and bacteriophage sequences of C. perfringens. A phiSM101 muramidase gene (psm) revealed by this study can be assumed to encode an N-acetylmuramidase, since the N-terminal catalytic domain deduced from the gene shows high homology of those of N-acetylmuramidases. The psm gene is characteristic in that it is present in phiSM101, an episomal phage of enterotoxigenic C. perfringens type A strain, SM101, and also in that homologous genes are present in the genomes of all five C. perfringens toxin types. The psm gene was cloned and expressed in Escherichia coli as a protein histidine-tagged at the N-terminus (Psm-his). Psm-his was purified to homogeneity by nickel-charged immobilized metal affinity chromatography and anion-exchange chromatography. The purified enzyme lysed cells of all C. perfringens toxin types but not other clostridial species tested, as was shown by a turbidity reduction assay. These results indicate the Psm-his is useful as a cell-wall lytic enzyme and also suggest that it is potentially useful for biocontrol of this organism.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki-cho, Kita-gun, Kagawa, Japan. microbio@med.kagawa-u.ac.jp
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nariya
authors.forename: Shigeru
authors.initials: S
authors.lastname: Miyata
authors.forename: Eiji
authors.initials: E
authors.lastname: Tamai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekiya
authors.forename: Jun
authors.initials: J
authors.lastname: Maki
authors.forename: Akinobu
authors.initials: A
authors.lastname: Okabe
mesh_terms: D001433:Bacteriolysis; D001435:Bacteriophages / Q000201:enzymology* / Q000302:isolation & purification; D002846:Chromatography, Affinity / Q000379:methods; D003001:Cloning, Molecular; D003016:Clostridium perfringens / Q000821:virology*; D010450:Endopeptidases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006026:Glycoside Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; C026255:endo-N-acetylmuramidase; D010450:Endopeptidases; C001143:endolysin