Regulatory interactions in Arabidopsis thaliana acetohydroxyacid synthase

FEBS Letters

Duggleby, Ronald G¹  Lee, Yu-Ting¹ 

[1] Centre for Protein Structure, Function and Engineering, Department of Biochemistry and Molecular Biology, University of Queensland, Brisbane, Qld. 4072, Australia

关键词: Acetohydroxyacid synthase;    Branched-chain amino acid;    Enzyme inhibition;    Enzyme regulation;    Subunit;    AHAS;    acetohydroxyacid synthase;    K i app;    apparent inhibition constant;   

DOI  :  10.1016/S0014-5793(02)02253-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Acetohydroxyacid synthase (AHAS; EC 4.1.3.18) contains catalytic and regulatory subunits, the latter being required for sensitivity to feedback regulation by leucine, valine and isoleucine. The regulatory subunit of Arabidopsis thaliana AHAS possesses a sequence repeat and we have suggested previously that one repeat binds leucine while the second binds valine or isoleucine, with synergy between the two sites. We have mutated four residues in each repeat, based on a model of the regulatory subunit. The data confirm that there are separate leucine and valine/isoleucine sites, and suggest a complex pathway for regulatory signal transmission to the catalytic subunit.

【 授权许可】

Unknown