Hu Yilin, Fay Aaron W, Ribbe Markus W
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA.
Proc Natl Acad Sci U S A. 2005 Mar 1;102(9):3236-41. doi: 10.1073/pnas.0409201102. Epub 2005 Feb 22.
The biosynthesis of the FeMo cofactor (FeMoco) of Azotobacter vinelandii nitrogenase presumably starts with the production of its Fe/S core by NifB (the nifB gene product). This core is subsequently processed on the alpha2beta2 tetrameric NifEN complex (formed by the nifE and nifN gene products). In this article, we identify a NifEN-bound FeMoco precursor form that can be converted to fully assembled FeMoco in a so-called FeMoco-maturation assay containing only purified components. We also establish that only molybdate, homocitrate, MgATP, and Fe protein are essential for FeMoco maturation. The FeMoco-maturation assay described here will further address the remaining questions related to the assembly mechanism of the ever-intriguing FeMoco.
棕色固氮菌固氮酶的铁钼辅因子（FeMoco）的生物合成可能始于由NifB（nifB基因产物）产生其铁硫核心。随后，该核心在α2β2四聚体NifEN复合物（由nifE和nifN基因产物形成）上进行加工。在本文中，我们鉴定出一种与NifEN结合的FeMoco前体形式，它可以在仅包含纯化成分的所谓FeMoco成熟测定中转化为完全组装的FeMoco。我们还确定，只有钼酸盐、高柠檬酸盐、MgATP和铁蛋白对FeMoco成熟至关重要。这里描述的FeMoco成熟测定将进一步解决与这个一直引人入胜的FeMoco组装机制相关的剩余问题。
