title: Difference in protein substrate specificity between hemorrhagic toxin and lethal toxin from Clostridium sordellii.
abstract: The hemorrhagic toxin (HT) from Clostridium sordellii is pharmacologically related to Clostridium difficile toxins A and B and Clostridium sordellii lethal toxin which have been recently identified as mono-glucosyl-transferases. Here we report that HT, which is coexpressed with lethal toxin, is also a glucosyltransferase. Whereas lethal toxin glucosylates the Rho subfamily proteins Rac and Cdc42 and the Ras subfamily proteins H-Ras and Rap, the substrate specificity of HT is strictly confined to the Rho subfamily proteins Rho, Rac and Cdc42. Comparable to lethal toxin, transferase activity of HT is stimulated by Mn2+. Acceptor amino acid in Rho was identified by mutagenesis as threonine-37. C. sordellii HT is a novel member of the family of clostridial mono-glucosyl-transferases, a family which modifies the Rho and Ras GTPases.
authors.affiliation: Institut für Pharmakologie und Toxikologie der Albert-Ludwigs-Universität Freiburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Genth
authors.forename: F
authors.initials: F
authors.lastname: Hofmann
authors.forename: J
authors.initials: J
authors.lastname: Selzer
authors.forename: G
authors.initials: G
authors.lastname: Rex
authors.forename: K
authors.initials: K
authors.lastname: Aktories
authors.forename: I
authors.initials: I
authors.lastname: Just
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism*; D002384:Catalysis; D003013:Clostridium / Q000201:enzymology / Q000378:metabolism*; D006031:Glycosylation; D016695:Glycosyltransferases / Q000378:metabolism; D051379:Mice; D013379:Substrate Specificity
chemical_list: D001427:Bacterial Toxins; C072293:hemorrhagic toxin HT, Clostridium sordellii; C072292:lethal toxin LT, Clostridium sordellii; D016695:Glycosyltransferases