The mechanism for nitrogenase including all steps

Mechanism of nitrogenase switch-off by oxygen.

Oxygen caused a reversible inhibition (switch-off) of nitrogenase activity in whole cells of four strains of diazotrophs, the facultative anaerobe Klebsiella pneumoniae and three strains of photosynthetic bacteria (Rhodopseudomonas sphaeroides f. sp. denitrificans and Rhodopseudomonas capsulata strains AD2 and BK5). In K. pneumoniae 50% inhibition of acetylene reduction was attained at an O2 co...

Catalytic activities of NifEN: implications for nitrogenase evolution and mechanism.

NifEN is a key player in the biosynthesis of nitrogenase MoFe protein. It not only shares a considerable degree of sequence homology with the MoFe protein, but also contains clusters that are homologous to those found in the MoFe protein. Here we present an investigation of the catalytic activities of NifEN. Our data show that NifEN is catalytically competent in acetylene (C(2)H(2)) and azide (...

Mechanism of Nitrogen Fixation by Nitrogenase: The Next Stage

All intermediates of the arsenate reductase mechanism, including an intramolecular dynamic disulfide cascade.

The mechanism of pI258 arsenate reductase (ArsC) catalyzed arsenate reduction, involving its P-loop structural motif and three redox active cysteines, has been unraveled. All essential intermediates are visualized with x-ray crystallography, and NMR is used to map dynamic regions in a key disulfide intermediate. Steady-state kinetics of ArsC mutants gives a view of the crucial residues for cata...

The Chemical Evolution of a Nitrogenase Model, 20 Alkyl Molybdates(VI) and the Mechanism of Hydrocarbon Production by Nitrogenase [1]

Colorless alkylmolybdates(VI) of composition R-M0O3are generated in aqueous solutions by the alkaline hydrolysis of complexes R-Mo(Bpy)(0)aBr (Bpy = 2,2'-bipyridyl, R = CH3 and higher alkyl). At room temperature in alkaline aqueous solution, the new organometallic derivatives of oxomolybdate(VI) are remarkably resistant against Mo-C bond hydrolysis. Decomposition occurs more rapidly on heating,...