York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, United Kingdom.
J Am Chem Soc. 2010 Aug 25;132(33):11455-7. doi: 10.1021/ja1053576.
Maleate isomerase (MI), a member of the Asp/Glu racemase superfamily, catalyzes cis-trans isomerization of the C2-C3 double bond in maleate to yield fumarate. Mutational studies, in conjunction with the structure of the C194A mutant of Nocardia farcinica MI cocrystallized with maleate, have revealed an unprecedented mode of catalysis for the superfamily in which the isomerization reaction is initiated by nucleophilic attack of cysteine at the double bond, yielding a covalent succinylcysteine-like intermediate.
顺丁烯二酸异构酶（MI）属于天冬氨酸/谷氨酸外消旋酶超家族，能够催化马来酸中 C2-C3 双键的顺反异构化，生成富马酸。突变研究与 Nocardia farcinica MI 的 C194A 突变体与马来酸共结晶的结构相结合，揭示了该超家族前所未有的催化模式，其中异构化反应由双键处半胱氨酸的亲核攻击引发，生成类似琥珀酰半胱氨酸的共价中间体。
