乙酰辅酶A羧化酶的结构·功能及基因的研究进展

Research Progress on the Structure Function of Acetyl-CoA Carboxylase and Its Genes

乙酰辅酶A羧化酶(Acetyl-CoA carboxylase,ACCase)属于生物素包含酶类型Ⅰ,在生物体内催化乙酰辅酶A形成丙二酰辅酶A。在植物中乙酰辅酶A羧化酶主要有异质型和同质型2种;在动物中乙酰辅酶A羧化酶属同质型,分为ACC1和ACC2 2种类型。主要介绍了分布于双子叶植物以及非禾本科单子叶植物的质体中的异质型ACCase的亚基组成、结构、功能及其编码基因。ACCase由生物素羧化酶(Biotincarboxylase,BC)亚基、生物素羧基载体蛋白亚基(Biotincarboxyl Camer Protein,BCCP)、羧基转移酶的α-CT亚基和β-CT亚基4种亚基构成,有3个功能结构域,即BC功能结构域、BCCP功能结构域以及CT功能结构域。除β-CT亚基由质体基因编码外,其他亚基由核基因编码,在细胞质中合成后转运到质体中组成功能蛋白,参与脂肪酸的合成。

Acetyl-CoA carboxylase（ACCase） belongs to biotin-containing enzymeⅠ,in vivo it catalyzes the formation of malonyl-CoA from acetyl-CoA.In plants,there are mainly two types of heterogeneous and homogeneous ACCase.In animals,ACCase belongs to homogeneous and including two types,namely,ACC1 and ACC2.This paper introduced subunits composition,structure,function and code genes of heterogeneous ACCase in the plastid of dicotyledons and non-cereal monocotyledons.The ACCase consists of four kinds of subunits,such as the biotin-carboxylase subunit（BC）,the biotin-carboxyl carrier protein subunit（BCCP）,the α-CT subunit and β-CT subunit of carboxyl transferase,and it has three function domains,i.e.BC function domain and BCCP function domain and CT function domain.Except that β-CT subunit is encoded by the plastid gene encoding,the other subunits are encoded by nuclear genes encoding,synthesized in the cytoplasm and then transferring to the plastid forming functional protein in fatty acid synthesis.