Naud I, Vinçon M, Garin J, Gaillard J, Forest E, Jouanneau Y
Laboratoire de Biochimie Microbienne (CNRS URA 1130 alliée à l'INSERM), Département de Biologie Moléculaire et Structurale, Grenoble, France.
Eur J Biochem. 1994 Jun 15;222(3):933-9. doi: 10.1111/j.1432-1033.1994.tb18942.x.
A new ferredoxin has been purified from the photosynthetic bacterium Rhodobacter capsulatus. It is the sixth ferredoxin to be isolated from this bacterium and it was called FdVI. Its primary structure was established based on amino acid sequence analysis of the protein and of peptides derived from it. It is composed of 106 residues including five cysteines. The calculated mass of the polypeptide is 11,402.6 Da which matches the experimental value determined by electrospray mass spectrometry. Amino acid sequence comparison revealed that ferredoxin VI (FdVI) is strikingly similar to a ferredoxin from Caulobacter crescentus and to the putidaredoxin from Pseudomonas putida. FdVI exhibited an ultraviolet-visible absorption spectrum typical for a [2Fe-2S] ferredoxin. EPR spectroscopy of the reduced protein showed a nearly axial signal similar to that of mitochondrial and P. putida ferredoxins. FdVI is biosynthesized in cells growing anaerobically under either nitrogen-sufficient or nitrogen-deficient conditions. Although the function of FdVI is unknown, its structural resemblance to [2Fe-2S] ferredoxins known to transfer electrons to oxygenases such as P-450 cytochromes, suggests that FdVI may have a similar role in R. capsulatus.
一种新的铁氧化还原蛋白已从光合细菌荚膜红细菌中纯化出来。它是从这种细菌中分离出的第六种铁氧化还原蛋白，被命名为FdVI。其一级结构是基于对该蛋白质及其衍生肽段的氨基酸序列分析确定的。它由106个残基组成，包括5个半胱氨酸。该多肽的计算质量为11402.6道尔顿，与通过电喷雾质谱法测定的实验值相符。氨基酸序列比较显示，铁氧化还原蛋白VI（FdVI）与新月柄杆菌的一种铁氧化还原蛋白以及恶臭假单胞菌的恶臭铁氧化还原蛋白极为相似。FdVI呈现出典型的[2Fe-2S]铁氧化还原蛋白的紫外可见吸收光谱。还原态蛋白的电子顺磁共振光谱显示出一个与线粒体和恶臭假单胞菌铁氧化还原蛋白类似的近乎轴向的信号。FdVI在氮充足或氮缺乏条件下厌氧生长的细胞中生物合成。尽管FdVI的功能尚不清楚，但其与已知能将电子传递给诸如P-450细胞色素等加氧酶的[2Fe-2S]铁氧化还原蛋白在结构上的相似性表明，FdVI在荚膜红细菌中可能具有类似的作用。
