Sasaki Y, Hakamada K, Suama Y, Nagano Y, Furusawa I, Matsuno R
Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan.
J Biol Chem. 1993 Nov 25;268(33):25118-23.
The gene product of an open reading frame of the chloroplast genome, accD, that has sequence similarity with a subunit of acetyl-CoA carboxylase from Escherichia coli was detected immunochemically in pea chloroplasts. The apparent molecular mass of the accD protein was 87 kDa on SDS-polyacrylamide gel electrophoresis. The protein was acidic and had less mobility than the calculated value, 67,116. Acetyl-CoA carboxylase activity solubilized from pea chloroplasts was inhibited by antibodies against recombinant accD protein. The antibodies precipitated a polypeptide of 35 kDa containing biotin and a polypeptide of 91 kDa together with the 87-kDa-accD protein. The accD protein formed a complex with the molecular mass of about 700 kDa, probably with the 35- and 91-kDa proteins. These results indicate that the chloroplast-encoded polypeptide, accD protein, is a component of a functional acetyl-CoA carboxylase in chloroplasts and this enzyme is a multi-subunit complex, like that from E. coli. The synthesis of accD protein was not induced by light.
叶绿体基因组一个开放阅读框的基因产物accD，其序列与大肠杆菌乙酰辅酶A羧化酶的一个亚基相似，已通过免疫化学方法在豌豆叶绿体中检测到。在SDS-聚丙烯酰胺凝胶电泳上，accD蛋白的表观分子量为87 kDa。该蛋白呈酸性，迁移率低于计算值67,116。从豌豆叶绿体中溶解的乙酰辅酶A羧化酶活性受到抗重组accD蛋白抗体的抑制。这些抗体沉淀出一条含有生物素的35 kDa多肽和一条91 kDa多肽以及87 kDa的accD蛋白。accD蛋白与分子量约为700 kDa的复合物形成，可能与35 kDa和91 kDa的蛋白结合。这些结果表明，叶绿体编码的多肽accD蛋白是叶绿体中功能性乙酰辅酶A羧化酶的一个组成部分，并且这种酶是一个多亚基复合物，类似于大肠杆菌中的酶。accD蛋白的合成不受光诱导。
