Requirement of NifX and Other nif Proteins for In Vitro Biosynthesis of the Iron-Molybdenum Cofactor of Nitrogenase
The iron-molybdenum cofactor (FeMo-co), located at the active site of the molybDENum nitrogenase, is one of the most complex metal cofactors known to date and insights are starting to be provided into the structures of the FeMo- co biosynthetic intermediates and into the biochemical details of Fe Mo-co synthesis.
In vitro synthesis of the iron-molybdenum cofactor of nitrogenase. Purification and characterization of NifB cofactor, the product of NIFB protein.
In vitro synthesis of the iron-molybdenum cofactor of nitrogenase.
- V. K. Shah, J. Imperial, R. Ugalde, P. Ludden, W. Brill
- Biology, ChemistryProceedings of the National Academy of Sciences…
- 1 March 1986
Properties of the partially purified dinitrogenase activated by FeMo-co synthesized in vitro were comparable to those of dinitrogensase from the wild-type organism; e.g., ratios of acetylene- to nitrogen-reduction activities, as well as those ofacetylene reduction activities to EPR spectrum peak height at g = 3.65, were very similar.
Purification and characterization of the nifN and nifE gene products from Azotobacter vinelandii mutant UW45.
- T. Paustian, V. K. Shah, G. Roberts
- BiologyProceedings of the National Academy of Sciences…
- 1 August 1989
The protein (hereafter referred to as NIFNE) was found to contain equimolar amounts of the nifN and -E gene products and have a native molecular mass of 200 +/- 10 kDa, which indicates an alpha 2 beta 2 structure.
Molybdenum in nitrogenase.
The biochemical process described by nitrogen fixation is the reduction of N2 to NH3, which can then be used for the synthesis of amino acids, nucleic acids, and other essential nitrogenous compounds, which ranks with photosynthesis as a process of fundamental importance to all life on earth.
Isolation of an iron-molybdenum cofactor from nitrogenase.
The FeMoCo might be used as a model for synthesizing catalysts for chemical nitrogen fixation and knowledge of the structure of this cofactor should be useful for understanding the role of molybdenum at the active site of nitrogenase, role of ligands close to moly bdenum in electron and proton transfer, and the catalytic mechanism of nitrogen fixation.
Nitrogenase. IV. Simple method of purification to homogeneity of nitrogenase components from Azotobacter vinelandii.
Apodinitrogenase: purification, association with a 20-kilodalton protein, and activation by the iron-molybdenum cofactor in the absence of dinitrogenase reductase.
The Azotobacter vinelandii mutant strain UW45 contains a mutation in the nifB gene and produces an inactive dinitrogenase protein that can be activated by the addition of purified iron-molybdenum cofactor (FeMoco), which has now been purified 96-fold to greater than 95% purity and is FeMoco-activatable.
Citrate substitutes for homocitrate in nitrogenase of a nifV mutant of Klebsiella pneumoniae.
The response of maximum velocities to changes in pH for both the wild-type and the NifV- dinitrogenase was compared and no substantial differences were observed, but there are minor differences.
The nifY product of Klebsiella pneumoniae is associated with apodinitrogenase and dissociates upon activation with the iron-molybdenum cofactor
There are aspects of the dissociation and insertion process in K. pneumoniae that are different from that in Azotobacter vinelandii.