A membrane-bound monoheme cytochrome c551 of a novel type is the immediate electron donor to P840 of the Chlorobium vibrioforme photosynthetic reaction center complex.
A membrane-bound monoheme cytochrome c551 of a novel type is the immediate electron donor to P840 of the Chlorobium vibrioforme photosynthetic reaction center complex.
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新型膜结合单血红素细胞色素c551是绿菌弧菌光合反应中心复合体P840的直接电子供体。
DOI：
10.1016/s0021-9258(19)36808-5
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
H. Scheller
中科院分区：
文献类型：
--
作者：
J. S. Okkels;B. Kjaer;O. Hansson;I. Svendsen;B. Møller;H. Scheller
从绿色硫细菌弧菌Chlorobium vibrioforme中分离到一个光合反应中心复合物。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示多肽的表观分子量为80，40，18，15，9和6 kDa。仅18-kDa多肽用血红素特异性试剂3，3 '，5，5'-四甲基联苯胺染色。氧化减还原差谱显示存在大约一个血红素/P840和细胞色素c551。闪光光解的P840其次是再还原的P840+和细胞色素c551的氧化，都与双相动力学与t1/2值为7和50微秒。使用衍生自18-kDa多肽的N-末端氨基酸序列的寡核苷酸探针，分离基因组克隆。我们命名为cycA的基因序列预测了单个血红素结合位点（Cys-Asn-Lys-Cys-His）。621个碱基对的开放阅读框架编码一个22，858 Da的脱辅基蛋白，具有三个预测的跨膜α-螺旋。没有广泛的序列相似性，发现其他细胞色素。北方印迹表明cycA基因转录为单顺反子mRNA。Southern杂交结果表明，在C. Vibrioforme和Chlorobium tepidum基因组。C.弧菌属于一类新的C型细胞色素。目前的光合反应中心复合物的进化观的影响进行了讨论。
A photosynthetic reaction center complex has been isolated from the green sulfur bacterium Chlorobium vibrioforme. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveals polypeptides with apparent molecular masses of 80, 40, 18, 15, 9, and 6 kDa. Only the 18-kDa polypeptide is stained with 3,3‘,5,5‘-tetramethylbenzidine, a heme-specific reagent. Oxidized minus reduced difference spectra show the presence of approximately one heme/P840 and the presence of a cytochrome c551. Flash photolysis of P840 was followed by rereduction of P840+ and oxidation of cytochrome c551, both with a biphasic kinetic with t1/2 values of 7 and 50 microseconds. Using oligonucleotide probes derived from an N-terminal amino acid sequence of the 18-kDa polypeptide, a genomic clone was isolated. The sequence of the gene, which we designate cycA, predicts a single heme binding site (Cys-Asn-Lys-Cys-His). The 621-base pair open reading frame encodes an apoprotein of 22,858 Da with three predicted membrane-spanning alpha-helices. No extensive sequence similarity is found to other cytochromes. Northern blotting indicates that the cycA gene is transcribed as a monocistronic mRNA. Southern blotting shows the presence of only one cycA gene in the C. vibrioforme and Chlorobium tepidum genomes. The unique membrane-bound monoheme cytochrome c551 of C. vibriforme is assigned to a new class of c-type cytochromes. The implications for the current view of evolution of photosynthetic reaction center complexes are discussed.
影响因子：
2.9
作者：
FLING, SP;GREGERSON, DS
通讯作者：
GREGERSON, DS
细胞色素和光合作用的进化。
DOI：
10.1016/s0005-2728(05)80263-4
发表时间：
1991
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Meyer,TE
通讯作者：
Meyer,TE