Mechanisms and structures of crotonase superfamily enzymes - How nature controls enolate and oxyanion reactivity

作者：Hamed R B; Batchelar E T; Clifton I J^*; Schofield C J

来源：Cellular and Molecular Life Sciences, 2008, 65(16): 2507-2527.

DOI：10.1007/s00018-008-8082-6

• crotonase superfamily
• oxyanion hole
• enolate intermediates
• coenzyme A
• beta-oxidation
• proteases

Structural and mechanistic studies on the crotonase superfamily (CS) are reviewed with the aim of illustrating how a conserved structural platform can enable catalysis of a very wide range of reactions. Many CS reactions have precedent in the 'carbonyl' chemistry of organic synthesis; they include alkene hydration/isomerization, aryl-halide dehalogenation, (de)carboxylation, CoA ester and peptide hydrolysis, fragmentation of beta-diketones and C-C bond formation, cleavage and oxidation. CS enzymes possess a canonical fold formed from repeated beta beta alpha units that assemble into two approximately perpendicular beta-sheets surrounded by alpha-helices. CS enzymes often, although not exclusively, oligomerize as trimers or dimers of trimers. Two conserved backbone NH groups in CS active sites form an oxyanion 'hole' that can stabilize enolate/oxyanion intermediates. The range and efficiency of known CS-catalyzed reactions coupled to their common structural platforms suggest that CS variants may have widespread utility in biocatalysis.

• 出版日期2008-8