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Comparative electronic structures of nitrogenase FeMoco and FeVco.

ABSTRACT: An investigation of the active site cofactors of the molybdenum and vanadium nitrogenases (FeMoco and FeVco) was performed using high-resolution X-ray spectroscopy. Synthetic heterometallic iron-sulfur cluster models and density functional theory calculations complement the study of the MoFe and VFe holoproteins using both non-resonant and resonant X-ray emission spectroscopy. Spectroscopic data show the presence of direct iron-heterometal bonds, which are found to be weaker in FeVco. Furthermore, the interstitial carbide is found to perturb the electronic structures of the cofactors through highly covalent Fe-C bonding. The implications of these conclusions are discussed in light of the differential reactivity of the molybdenum and vanadium nitrogenases towards various substrates. Possible functional roles for both the heterometal and the interstitial carbide are detailed.

SUBMITTER: Rees JA

PROVIDER: S-EPMC5322470 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature

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Comparative electronic structures of nitrogenase FeMoco and FeVco.

Rees Julian A JA Bjornsson Ragnar R Kowalska Joanna K JK Lima Frederico A FA Schlesier Julia J Sippel Daniel D Weyhermüller Thomas T Einsle Oliver O Kovacs Julie A JA DeBeer Serena S

Dalton transactions (Cambridge, England : 2003) 20170201 8

An investigation of the active site cofactors of the molybdenum and vanadium nitrogenases (FeMoco and FeVco) was performed using high-resolution X-ray spectroscopy. Synthetic heterometallic iron-sulfur cluster models and density functional theory calculations complement the study of the MoFe and VFe holoproteins using both non-resonant and resonant X-ray emission spectroscopy. Spectroscopic data show the presence of direct iron-heterometal bonds, which are found to be weaker in FeVco. Furthermor ...[more]

PMID: 28154874

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