title: Analysis of the catalytic site of the actin ADP-ribosylating Clostridium perfringens iota toxin.
abstract: The enzyme component of actin ADP-ribosylating Clostridium perfringens iota toxin was affinity labelled by UV irradiation in the presence of [carbonyl-14C]NAD. A peptide containing the radiolabel was generated by CNBr cleavage and subsequent proteolysis with trypsin. Its amino acid sequence is Gly-Ser-Pro-Gly-Ala-Tyr-Leu-Ser-Ala-Ile-Pro-Gly-Tyr-Ala-Gly-X-Tyr-Glu-Va l-Leu-Leu-Asn-His-Gly-Ser-Lys corresponding with the region Gly-363 through Lys-388 in the C. perfringens iota toxin. Mass spectrometric data as well as results of the PTH-amino acid analysis are in line with a modification of a glutamic acid side chain located at position 378. Therefore, in addition to Glu-380, as could be concluded by analogy with other ADP-ribosyltransferases, Glu-378 may play a pivotal role in the active site of C. perfringens iota toxin.
authors.affiliation: Institute for Biotechnology, Department of Biochemistry, Faculty of Medicine, University of Gent, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: van Damme
authors.forename: M
authors.initials: M
authors.lastname: Jung
authors.forename: F
authors.initials: F
authors.lastname: Hofmann
authors.forename: I
authors.initials: I
authors.lastname: Just
authors.forename: J
authors.initials: J
authors.lastname: Vandekerckhove
authors.forename: K
authors.initials: K
authors.lastname: Aktories
mesh_terms: D036002:ADP Ribose Transferases; D000199:Actins / Q000378:metabolism*; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000345:Affinity Labels; D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D003016:Clostridium perfringens; D003488:Cyanogen Bromide; D018698:Glutamic Acid; D008969:Molecular Sequence Data; D009243:NAD; D010446:Peptide Fragments / Q000737:chemistry; D010777:Photochemistry; D014466:Ultraviolet Rays
chemical_list: D000199:Actins; D000345:Affinity Labels; D001427:Bacterial Toxins; D010446:Peptide Fragments; C050737:iota toxin, Clostridium perfringens; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D018698:Glutamic Acid; D036002:ADP Ribose Transferases; D003488:Cyanogen Bromide