Molecular cloning and expression of heteromeric ACCase subunit genes from Jatropha curcas
Molecular cloning and expression of heteromeric ACCase subunit genes from Jatropha curcas
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DOI：
10.1016/j.plantsci.2011.01.007
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发表时间：
2011-04-01
期刊：
影响因子：
5.2
通讯作者：
Yin, Zhongchao
中科院分区：
文献类型：
--
作者：
Gu, Keyu;Chiam, Huihui;Yin, Zhongchao
乙酰辅酶A羧化酶（ACCase）催化乙酰辅酶A的生物素依赖性羧化以产生丙二酰辅酶A，丙二酰辅酶A是长链脂肪酸生物合成中必不可少的第一步。ACCase作为多亚基酶存在于大多数原核生物以及大多数植物和藻类的叶绿体中，而它作为多结构域酶存在于大多数真核生物的内质网中。高等植物的ACCase由4个亚基组成：羧基转移酶α亚基（α-CT，由accA基因编码）、生物素羧基载体蛋白（BCCP，由accB基因编码）、生物素羧化酶（BC，由accC基因编码）和羧基转移酶β亚基（β-CT，由accD基因编码）。在这项研究中，我们克隆和鉴定的基因accA，accB 1，accC和accD编码的异聚ACC酶亚基的麻风树（麻风树curcas），一个潜在的生物燃料植物。从麻风树cDNA文库中用5' RACE法分离了这四个亚基基因的全长cDNA，而基因组克隆则从麻风树BAC文库中获得。它们分别编码771个氨基酸（aa）的α-CT、286个氨基酸的BCCP 1、537个氨基酸的BC和494个氨基酸的β-CT。单拷贝的accA、accB 1和accC基因是核基因，而accD基因位于叶绿体基因组中。麻风树α-CT、BCCP 1、BC和β-CT与其它高等植物同源物在氨基酸水平上具有高度的同源性，并且包含ACCase活性的所有保守结构域。accA、accB 1、accC和accD基因在麻风树属植物叶片和胚乳中的时空表达受植物发育和环境因子的调控。(C)2011爱思唯尔爱尔兰有限公司保留所有权利。
Acetyl-CoA carboxylase (ACCase) catalyzes the biotin-dependent carboxylation of acetyl-CoA to produce malonyl-CoA, which is the essential first step in the biosynthesis of long-chain fatty acids. ACCase exists as a multi-subunit enzyme in most prokaryotes and the chloroplasts of most plants and algae, while it is present as a multi-domain enzyme in the endoplasmic reticulum of most eukaryotes. The heteromeric ACCase of higher plants consists of four subunits: an alpha-subunit of carboxyltransferase (alpha-CT, encoded by accA gene), a biotin carboxyl carrier protein (BCCP, encoded by accB gene), a biotin carboxylase (BC, encoded by accCgene) and a beta-subunit of carboxyltransferase (beta-CT, encoded by accD gene). In this study, we cloned and characterized the genes accA, accB1, accC and accD that encode the subunits of heteromeric ACCase in Jatropha (Jatropha curcas), a potential biofuel plant. The full-length cDNAs of the four subunit genes were isolated from a Jatropha cDNA library and by using 5' RACE, whereas the genomic clones were obtained from a Jatropha BAC library. They encode a 771 amino acid (aa) alpha-CT, a 286-aa BCCP1, a 537-aa BC and a 494-aa beta-CT, respectively. The single-copy accA, accB1 and accC genes are nuclear genes, while the accD gene is located in chloroplast genome. Jatropha alpha-CT, BCCP1, BC and beta-CT show high identity to their homologues in other higher plants at amino acid level and contain all conserved domains for ACCase activity. The accA, accB1, accC and accD genes are temporally and spatially expressed in the leaves and endosperm of Jatropha plants, which are regulated by plant development and environmental factors. (C) 2011 Elsevier Ireland Ltd. All rights reserved.