Conformational analysis of the GTP‐binding protein MxA using limited proteolysis

FEBS Letters

Muthukumaraswamy, Karthika¹  Mittal, Rohit¹  Jatiani, Shashidhar S¹  Varne, Anjali¹ 

[1]Tata Institute of Fundamental Research, Bombay, India

关键词: G-protein;    MxA;    Proteolysis;    Nucleotide exchange;    GDP;    guanosine diphosphate;    GTP;    guanosine triphosphate;    GppNHp;    imidoguanosine triphosphate (a non-hydrolyzable analogue of GTP);    PMSF;    phenylmethyl sulfonyl fluoride;    SDS–PAGE;    sodium dodecyl sulfate–polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(02)02519-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Guanosine triphosphate (GTP)-binding proteins are known to function as molecular switches that cycle between GTP-bound and guanosine diphosphate (GDP)-bound states. Switching is achieved by the fact that G-proteins in the GTP-bound conformation can interact with a certain set of effector molecules while they interact with a different set of partners in their GDP-bound conformation. The antiviral properties of the interferon-induced MxA protein are critically dependent on the ability of MxA to bind GTP. Using limited proteolysis we analyzed the conformations of the MxA protein under nucleotide-free, GDP-bound, and GTP-bound conditions. We find that whereas the conformations of nucleotide-free MxA and GDP-bound MxA are essentially similar, GTP-binding causes a dramatic change in the conformation of MxA.

【 授权许可】

Unknown