Vanadium nitrogenase FeVco

Vanadium nitrogenase is produced by certain bacteria grown in molybdenum-deficient environments. It is effective in the reduction of N2 and other nitrogenase substrates, although with less activity than the Mo—Nase. The enzyme resembles the Mo analogue (see Sections 17-E-10 and 18-C-13) in the construction and structure of the prosthetic groups, as well as in its functions.101 It consists of a FeV protein, FeVco, and an iron protein (a 4Fe—4S ferredoxin). 

Structure information on the FeVco of vanadium nitrogenases has been obtained from iron and vanadium K-edge X-ray absorption spectroscopy (XAS) (for background information, see Section 3.6.), in particular so from the extended (EXAFS) region. 

Fig. 5. Buildup of the vanadium-nitrogenase from A. chroococcum, and the proposed structure of the M cluster (FeVco). The light scatterer X has been proposed to be N.

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