Functional analysis of block 5, one of the highly conserved amino acid sequences in the 130‐kDa CryIVA protein produced by Bacillus thuringiensis subsp. israelensis

FEBS Letters

Yoshisue, Hajime¹  Ihara, Kentaro¹  Sakai, Hiroshi¹  Komano, Tohru¹  Nishimoto, Tomoyuki¹ 

[1]Laboratory of Biochemistry, Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Kyoto 606-01, Japan

关键词: δ-Endotoxin;    Insecticidal activity;    Thermal stability;    Bacillus thuringiensis;    B.;    Bacillus;    E;    Escherichia;    C;    Culex;    A;    Aedes;    kDa;    kilodalton(s);    h;    hour(s);    bp;    base pair(s);    PAGE;    polyacrylamide gel electrophoresis;    SDS;    sodium dodecyl sulfate;    Tris;    tris(hydroxymethyl)aminomethane;    DTT;    dithiothreitol;    EDTA;    ethylenediaminetetraacetic acid;    CAPS;    3-cyclohexylaminopropanesulfonic acid;    LC50;    is defined in detail in the text;   

DOI  :  10.1016/0014-5793(94)00604-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

There are five amino acid sequences highly conserved among Bacillus thuringiensis δ-endotoxins. We have changed the amino acid residues in block 5, one of the conserved sequences, of CryIVA. When the amino acid residues with charged side chains were replaced by others, the amount of production of the altered CryIVA protein was markedly decreased. It is suggested that the decrease is caused by the unstable conformation of the altered CryIVA protein molecule, as judged by digestion with trypsin and thermolysin. On the other hand, the substitution of amino acid residues in block 5 did not affect the insecticidal activity of CryIVA. These results strongly suggest that block 5 of CryIVA is one of the stability-determining elements of the protoxin molecule.

【 授权许可】

Unknown