X-ray Spectroscopic Observation of an Interstitial Carbide in NifEN-Bound FeMoco Precursor
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- 作者：Kyle M. Lancaster ; Yilin Hu ; Uwe Bergmann ; Markus W. Ribbe ; Serena DeBeer
- 刊名：The Journal of the American Chemical Society
- 出版年：2013
- 出版时间：January 16, 2013
- 年：2013
- 卷：135
- 期：2
- 页码：610-612
- 全文大小：217K
- 年卷期：v.135,no.2(January 16, 2013)
- ISSN：1520-5126
文摘
The iron鈥搈olybdenum cofactor (FeMoco) of nitrogenase contains a biologically unprecedented 渭6-coordinated C4鈥?/sup> ion. Although the role of this interstitial atom in nitrogenase catalysis is unknown, progress in understanding its biosynthetic origins has been made. Here we report valence-to-core Fe K尾 X-ray emission spectroscopy data to show that this C4鈥?/sup> ion is present in the Fe8S9 鈥淟-cluster,鈥?which is the immediate precursor to FeMoco prior to the insertion of molybdenum and coordination by homocitrate. These results accord with recent evidence supporting a role for the S-adenosylmethionine-dependent enzyme NifB in the incorporation of carbon into the FeMoco center of nitrogenase.