On the structure of the nickel/iron/sulfur center of the carbon monoxide dehydrogenase from Rhodospirillum rubrum: an x-ray absorption spectroscopy study.
On the structure of the nickel/iron/sulfur center of the carbon monoxide dehydrogenase from Rhodospirillum rubrum: an x-ray absorption spectroscopy study.
复制标题
红色红螺菌一氧化碳脱氢酶镍/铁/硫中心的结构：X 射线吸收光谱研究。
DOI：
10.1073/pnas.89.10.4427
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发表时间：
1992
影响因子：
11.1
通讯作者：
Hodgson,KO
中科院分区：
文献类型：
--
作者：
Tan,GO;Ensign,SA;Ciurli,S;Scott,MJ;Hedman,B;Holm,RH;Ludden,PW;Korszun,ZR;Stephens,PJ;Hodgson,KO
通过X射线吸收光谱法在Ni K边缘研究了来自红杜鹃（Rhodocellum rubrum）的一氧化碳脱氢酶（一氧化碳：（受体）氧化还原酶; EC 1.2.99.2）（Rr-CODH）的镍/铁/硫中心。扩展的X射线吸收精细结构数据表明，第一层Ni配位壳层由2.23A的2个S原子和1.87A的2-3个N/O原子组成。边缘结构表明在氧化和还原Rr-CODH中的扭曲四面体或五配位Ni环境。通过比较Rr-CODH与立方烷型团簇（Et 4 N）3[NiFe 3S 4（SEt）4]的第二壳层扩展X射线吸收精细结构数据，可以清楚地确定Rr-CODH中心的Ni不参与NiFe 3S 4立方烷团簇的核心。与结果一致的一个模型是单核Ni 2+位点，通过S-Cys或硫化物桥接到酶的一个或两个Fe 4S 4簇，其余的配位位点被另外的S-Cys或N/O-配位氨基酸残基占据。
The nickel/iron/sulfur center of the carbon monoxide dehydrogenase (carbon monoxide:(acceptor)oxidoreductase; EC 1.2.99.2) enzyme from Rhodospirillum rubrum (Rr-CODH) was studied by x-ray absorption spectroscopy at the Ni K edge. Extended x-ray absorption fine structure data show that the first Ni coordination shell consists of 2 S atoms at 2.23 A and 2-3 N/O atoms at 1.87 A. The edge structure indicates a distorted tetrahedral or five-coordinate Ni environment in both oxidized and reduced Rr-CODH. By comparing second-shell extended x-ray absorption fine structure data of Rr-CODH to that of (Et4N)3[NiFe3S4(SEt)4], a cubane-type cluster, it was clearly established that Ni in the Rr-CODH center is not involved in the core of a NiFe3S4 cubane cluster. One model consistent with the results is a mononuclear Ni2+ site, bridged by S-Cys or sulfide to one or both of the Fe4S4 clusters of the enzyme, with the remaining coordination sites occupied by additional S-Cys or N/O-liganding amino acid residues.