Publication Date:
2015-09-30
Description:
Nitrogenases are the enzymes by which certain microorganisms convert atmospheric dinitrogen (N2) to ammonia, thereby providing essential nitrogen atoms for higher organisms. The most common nitrogenases reduce atmospheric N2 at the FeMo cofactor, a sulfur-rich iron-molybdenum cluster (FeMoco). The central iron sites that are coordinated to sulfur and carbon atoms in FeMoco have been proposed to be the substrate binding sites, on the basis of kinetic and spectroscopic studies. In the resting state, the central iron sites each have bonds to three sulfur atoms and one carbon atom. Addition of electrons to the resting state causes the FeMoco to react with N2, but the geometry and bonding environment of N2-bound species remain unknown. Here we describe a synthetic complex with a sulfur-rich coordination sphere that, upon reduction, breaks an Fe-S bond and binds N2. The product is the first synthetic Fe-N2 complex in which iron has bonds to sulfur and carbon atoms, providing a model for N2 coordination in the FeMoco. Our results demonstrate that breaking an Fe-S bond is a chemically reasonable route to N2 binding in the FeMoco, and show structural and spectroscopic details for weakened N2 on a sulfur-rich iron site.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592811/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592811/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Coric, Ilija -- Mercado, Brandon Q -- Bill, Eckhard -- Vinyard, David J -- Holland, Patrick L -- GM065313/GM/NIGMS NIH HHS/ -- R01 GM065313/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Oct 1;526(7571):96-9. doi: 10.1038/nature15246. Epub 2015 Sep 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA. ; Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mulheim an der Ruhr, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26416755" target="_blank"〉PubMed〈/a〉
Keywords:
Binding Sites
;
Carbon/*chemistry
;
Electrons
;
Iron/*chemistry
;
Ligands
;
Molybdoferredoxin/chemistry/metabolism
;
Nitrogen/*chemistry
;
Nitrogenase/metabolism
;
Sulfur/*chemistry
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
