title: Cyt2Ba of Bacillus thuringiensis israelensis: activation by putative endogenous protease.
abstract: The gene cyt2Ba of Bacillus thuringiensis subsp. israelensis was cloned for expression, together with p20, in an acrystalliferous strain. The large hexagonal crystals formed were composed of Cyt2Ba, which facilitated its purification. Crystal solubilization in the presence of endogenous proteases (with spores and cell debris) enabled quick and simple procedure to obtain rather pure and active toxin species by cleavage between amino acid residues 34 and 35, most likely by a camelysin-like protease that was discovered in association with activated Cyt2Ba. The product of this cleavage displayed haemolytic activity comparable to that of exogenously activated Cyt2Ba. The sequence of this putative protease shares high homology with the cell envelope-bound metalloprotease (camelysin) of the closely related species Bacillus cereus.
authors.affiliation: Department of Chemical Engineering and Biotechnology, College of Judea and Samaria, Ariel 44837, Israel.
authors.forename: Marina
authors.initials: M
authors.lastname: Nisnevitch
authors.forename: Shmuel
authors.initials: S
authors.lastname: Cohen
authors.forename: Eitan
authors.initials: E
authors.lastname: Ben-Dov
authors.forename: Arieh
authors.initials: A
authors.lastname: Zaritsky
authors.forename: Yossef
authors.initials: Y
authors.lastname: Sofer
authors.forename: Rivka
authors.initials: R
authors.lastname: Cahan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000187:drug effects; D001413:Bacillus thuringiensis / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D003001:Cloning, Molecular / Q000379:methods; D004731:Endotoxins / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D006460:Hemolysin Proteins; D006461:Hemolysis; D007306:Insecticides / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D012995:Solubility
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C078117:20 kDa protein, Bacillus thuringiensis; D008666:Metalloendopeptidases; C438729:camelysin