title: Effect of accessory proteins P19 and P20 on cytolytic activity of Cyt1Aa from Bacillus thuringiensis subsp. israelensis in Escherichia coli.
abstract: The gene coding for the accessory protein P19 of Bacillus thuringiensis subsp. israelensis was expressed in Escherichia coli and its product was characterized. To investigate its putative role in delta-endotoxin crystallization as a P20-like polypeptide, each of the two encoding genes, p20 and p19, was cloned for inducible expression coordinatively with cyt1Aa. The latter is known to kill its transgenic host. P20 but not P19 stabilized Cyt1Aa and protected the host cells from its lethal effect. Neither GroEL nor GroES, expressed in trans, affected Cyt1Aa as did P20. The function of P20 is thus more specific than that of the chaperones, but that of P19 remains enigmatic. The correct sequence of p19, confirmed in all five isolates of B. thuringiensis subsp. israelensis, does not explain the slow electrophoretic mobility of its 179 amino acids product.
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel. ariehz@bgumail.bgu.ac.il
authors.forename: R
authors.initials: R
authors.lastname: Manasherob
authors.forename: A
authors.initials: A
authors.lastname: Zaritsky
authors.forename: E
authors.initials: E
authors.lastname: Ben-Dov
authors.forename: D
authors.initials: D
authors.lastname: Saxena
authors.forename: Z
authors.initials: Z
authors.lastname: Barak
authors.forename: M
authors.initials: M
authors.lastname: Einav
mesh_terms: D000595:Amino Acid Sequence; D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism* / Q000633:toxicity*; D001427:Bacterial Toxins; D001483:Base Sequence; D018835:Chaperonin 10 / Q000378:metabolism; D018834:Chaperonin 60 / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D006460:Hemolysin Proteins; D008969:Molecular Sequence Data
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D018835:Chaperonin 10; D018834:Chaperonin 60; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis