Enzymology, structure, and dynamics of acetohydroxy acid isomeroreductase

Acetohydroxy acid isomeroreductase is a key enzyme involved in the biosynth etic pathway of the amino acids isoleucine, valine, and leucine. This enzym e is of great interest in agrochemical research because it is present only in plants and microorganisms, making it a potential target for specific her bicides and fungicides. Moreover, it catalyzes an unusual two-step reaction that is of great fundamental interest. With a view to characterizing both the mechanism of inhibition by potential herbicides and the complex reactio n mechanism, various techniques of enzymology, molecular biology, mass spec trometry, X-ray crystallography, and theoretical simulation have been used. The results and conclusions of these studies are described briefly in this paper.