Okawara N, Ogata M, Yagi T, Wakabayashi S, Matsubara H
Department of Chemistry, Shizuoka University, Japan.
Biochimie. 1988 Dec;70(12):1815-20. doi: 10.1016/0300-9084(88)90043-0.
One of 2 ferredoxins, Fd II, purified from Desulfovibrio vulgaris Miyazaki (DvM) has been characterized and its complete amino acid sequence established. Fd II is composed of 63 amino acid residues and contains 7 cysteinyl residues but has only 4 iron atoms in an iron-sulfur cluster of a standard redox potential of -405 mV. The arrangement of cysteinyl residues in the protein suggests that some cysteinyl residues are not directly involved in ligation to the iron-sulfur cluster. Homology is recognized among Fd II (DvM), Fd I (D. desulfuricans Norway), Fd I (D. africanus Benghazi), and Fd (D. gigas). Although Fd I and Fd II in DvM are poorly homologous, the C-terminal half of Fd I is fairly homologous to the N-terminal half of Fd II. Fd II is 40% as effective as Fd I as an electron carrier for pyruvate dehydrogenase coupled with hydrogenase and cytochrome c3.
从普通脱硫弧菌宫崎株(DvM)中纯化得到的两种铁氧化还原蛋白之一——铁氧化还原蛋白II(Fd II),已被鉴定并确定了其完整的氨基酸序列。Fd II由63个氨基酸残基组成,含有7个半胱氨酰残基,但在标准氧化还原电位为 -405 mV的铁硫簇中仅含有4个铁原子。蛋白质中半胱氨酰残基的排列表明,一些半胱氨酰残基并不直接参与与铁硫簇的连接。在Fd II(DvM)、Fd I(脱硫脱硫弧菌挪威株)、Fd I(非洲脱硫弧菌班加西株)和Fd(巨大脱硫弧菌)之间存在同源性。尽管DvM中的Fd I和Fd II同源性较差,但Fd I的C端一半与Fd II的N端一半相当同源。作为丙酮酸脱氢酶与氢化酶和细胞色素c3偶联的电子载体,Fd II的效率是Fd I的40%。