Dalwani Subhadra, Wierenga Rik K
Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland.
Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland.
Curr Opin Struct Biol. 2023 Oct;82:102671. doi: 10.1016/j.sbi.2023.102671. Epub 2023 Aug 4.
The crotonase fold is generated by a framework of four repeats of a ββα-unit, extended by two helical regions. The active site of crotonase superfamily (CS) enzymes is located at the N-terminal end of the helix of the third repeat, typically being covered by a C-terminal helix. A major subset of CS-enzymes catalyzes acyl-CoA-dependent reactions, allowing for a diverse range of acyl-tail modifications. Most of these enzymes occur as trimers or hexamers (dimers of trimers), but monomeric forms are also observed. A common feature of the active sites of CS-enzymes is an oxyanion hole, formed by two peptide-NH hydrogen bond donors, which stabilises the negatively charged thioester oxygen atom of the reaction intermediate. Structural properties and possible use of these enzymes for biotechnological applications are discussed.
巴豆酸酶折叠结构由ββα单元的四个重复序列构成框架，并由两个螺旋区域延伸而成。巴豆酸酶超家族（CS）酶的活性位点位于第三个重复序列螺旋的N末端，通常被C末端螺旋覆盖。CS酶的一个主要亚类催化依赖于酰基辅酶A的反应，从而实现多种酰基尾部修饰。这些酶大多以三聚体或六聚体（三聚体的二聚体）形式存在，但也观察到单体形式。CS酶活性位点的一个共同特征是氧阴离子洞，由两个肽-NH氢键供体形成，它能稳定反应中间体带负电荷的硫酯氧原子。本文还讨论了这些酶的结构特性及其在生物技术应用中的潜在用途。
