Abstract
Biological nitrogen fixation is enabled by molybdenum-dependent nitrogenase enzymes, which effect the reduction of dinitrogen to ammonia using an Fe7MoS9C active site, referred to as the iron molybdenum cofactor or FeMoco. In this mini-review, we summarize the current understanding of the molecular and electronic structure of FeMoco. The advances in our understanding of the active site structure are placed in context with the parallel evolution of synthetic model studies. The recent discovery of Mo(III) in the FeMoco active site is highlighted with an emphasis placed on the important role that model studies have played in this finding. In addition, the reactivities of synthetic models are discussed in terms of their relevance to the enzymatic system.
Highlights
Molybdenum-dependent nitrogenase is a complex enzyme that catalyzes the formation of ammonia through the electrochemical reduction of dinitrogen at ambient temperature and pressure, utilizing eight electrons, eight protons and 16 MgATP molecules [1, 2]
The P-cluster is an eight-iron cluster that appears to serve as an electron-transfer site, while FeMo cofactor (FeMoco) is generally agreed to be the site of dinitrogen reduction
The FeMo cofactor consists of 7 irons, 1 molybdenum, 9 sulfides and an interstitial light atom that was recently identified as carbon by XES, ESEEM and high-resolution crystallography [3, 4]
Summary
Molybdenum-dependent nitrogenase is a complex enzyme that catalyzes the formation of ammonia through the electrochemical reduction of dinitrogen at ambient temperature and pressure, utilizing eight electrons, eight protons and 16 MgATP molecules [1, 2]. This complex cofactor, whose structural details have been elusive for so long, is capable of chemistry that is still a challenge for synthetic chemists to mimic. The total charge of the cofactor, the metal oxidation states and the electronic structure, all remain open questions—the answers to which are essential for any informed discussion of the molecular level mechanism of dinitrogen reduction. In this mini-review, we give a brief overview of the structural characterization of the enigmatic FeMoco cluster, including both molecular and electronic structure aspects. The reactivity of the model complexes is discussed in terms of its potential relevance to the enzyme chemistry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
