Gisselmann G, Klausmeier P, Schwenn J D
Biochemistry of Plants, Faculty of Biology, Ruhr University Bochum, Germany.
Biochim Biophys Acta. 1993 Aug 16;1144(1):102-6. doi: 10.1016/0005-2728(93)90037-g.
The structural gene of the ferredoxin:sulphite reductase (EC 1.8.7.1) from the cyanobacterium Synechococcus PCC7942 (formerly 'Anacystis nidulans') was cloned and sequenced. The gene termed 'sir' was detected by heterologous Southern hybridisation with the structural gene cysI from Escherichia coli encoding the iron-sulphur haemoprotein of the NADPH:sulphite reductase. The open reading frame is comprised of 1875 bp encoding for a polypeptide of M(r) 70.028. The deduced amino acid sequence is 35.6% identical with the enterobacterial iron-sulphur haemoprotein. This putative fd-dependent sulphite reductase is only distantly related to the fd-dependent nitrite reductase (binary matching coefficient SAB: 0.23) or with the NADPH-sulphite reductase (SAB: 0.32). Highly conserved residues are found within the two Cys clusters forming the reactive Fe4S4-sirohaem centre of the enzyme. Expression of the sir gene using a fusion vector gave a single gene product which is immunologically related with the fd-sulphite reductase from the wild-type bacterium.
克隆并测序了来自蓝藻聚球藻PCC7942（以前称为“巢状鱼腥藻”）的铁氧化还原蛋白：亚硫酸盐还原酶（EC 1.8.7.1）的结构基因。通过与编码NADPH：亚硫酸盐还原酶的铁硫血红蛋白的大肠杆菌结构基因cysI进行异源Southern杂交，检测到名为“sir”的基因。开放阅读框由1875个碱基对组成，编码一个分子量为70.028的多肽。推导的氨基酸序列与肠杆菌铁硫血红蛋白有35.6%的同源性。这种假定的依赖铁氧化还原蛋白的亚硫酸盐还原酶与依赖铁氧化还原蛋白的亚硝酸还原酶（二元匹配系数SAB：0.23）或与NADPH-亚硫酸盐还原酶（SAB：0.32）只有远缘关系。在形成该酶活性Fe4S4-丝氨酸血红素中心的两个半胱氨酸簇中发现了高度保守的残基。使用融合载体表达sir基因产生了单一的基因产物，该产物与野生型细菌的铁氧化还原蛋白-亚硫酸盐还原酶有免疫相关性。
