Biological Nitrogen Fixation
Nitrogenase is the only known biological catalyst capable of reducing inert atmospheric N2 to ammonia at ambient temperatures and pressure. The immense demand for ammonia to produce fertilizer makes this a crucial agricultural process, one which is currently met through industrial dinitrogen reduction by the Haber-Bosch process at exceedingly high temperature and pressure (400-500 °C and 150-250 atm of pressure), producing significant quantities of greenhouse gasses as byproducts. The molecular mechanism of catalysis by nitrogenase remains nebulous, but at present is understood to involve the transfer of 8 electrons to the site of catalysis, mediated by multiple protein binding-unbinding events and conformational changes. The nitrogenase subgroup performs fundamental studies into this process using advanced spectroscopic techniques, protein biochemistry, state-of-the-art molecular biology, crystallography, cryoEM, and molecular dynamics, to investigate electron transfer and protein dynamics during nitrogenase catalysis.
Principal members: Hannah, Robin
H.L. Rutledge, F.A. Tezcan. Electron Transfer in Nitrogenase, Chem. Rev. (2020).[PDF]
H.L Rutledge, J. Rittle, L.M. Williamson, W.A. Xu, D.M. Gagnon, F.A. Tezcan. Redox-dependent metastability of the nitrogenase P-cluster, J. Am. Chem. Soc. (2019).[PDF]
C.P. Owens, F.E.H. Katz, C.H. Carter, V.F. Oswald, F.A. Tezcan. Tyrosine-coordinated P-cluster in G. diazotrophicus nitrogenase: Evidence for the importance of O-based ligands in conformationally gated electron transfer, J. Am. Chem. Soc. (2016).[PDF]
C.P. Owens, F.E.H. Katz, C.H. Carter, M.A. Luca, F.A. Tezcan. Evidence for Functionally Relevant Encounter Complexes in Nitrogenase Catalysis, J. Am. Chem. Soc. (2015).[PDF]
F.A. Tezcan, J.T. Kaiser, J.B. Howard, D.C. Rees. Structural Evidence for Asymmetrical Nucleotide Interactions in Nitrogenase, J. Am. Chem. Soc. (2014).[PDF]