Nitrogenase Molybdenum-iron Protein, subunit B; domain 4
CYS 53(P cluster);ILE 465;HIS 482(Homocitrate);HIS 482(FeMoco)
GLN 182(Homocitrate);CYS 79;CYS 145(P cluster)
CYS 23;CYS 48;CYS 106;SER 141(P cluster)
CYS 94;CYS 129(4Fe-4S binding);SER 15(Magnesium binding)
Scheme 1, Scheme 2, Fig.3, Fig.4, p.571-575
Nitrogenase XII. Mossbauer studies of the MoFe protein from Clostridium pasteurianum W5.
Neutron small angle scattering of the Mo-Fe protein (nitrogenase) from Clostridium pasteurianum.
Molecular symmetry of the MoFe protein of nitrogenase. Structural homology/nitrogen fixation/x-ray crystallography.
Crystallographic properties of the MoFe proteins of nitrogenase from Clostridium pasteurianum and Azotobacter vinelandii.
Molecular basis of biological nitrogen fixation.
Distinct structural features of the alpha and beta subunits of nitrogenase molybdenum-iron protein of Clostridium pasteurianum: an analysis of amino acid sequences.
Comparison of redox and EPR properties of the molybdenum iron proteins of Clostridium pasteurianum and Azotobacter vinelandii nitrogenases.
Hydrogen-1 nuclear magnetic resonance of the nitrogenase iron protein (Cp2) from Clostridium pasteurianum.
E.p.r.-spectroscopic studies on the molybdenum-iron site of nitrogenase from Clostridium pasteurianum.
Role for the nitrogenase MoFe protein alpha-subunit in FeMo-cofactor binding and catalysis.
Pulsed electron paramagnetic resonance studies of the interaction of Mg-ATP and D2O with the iron protein of nitrogenase.
Crystallographic structure and functional implications of the nitrogenase molybdenum-iron protein from Azotobacter vinelandii.
Structural models for the metal centers in the nitrogenase molybdenum-iron protein.
Ionic interactions in the nitrogenase complex. Properties of Fe-protein containing substitutions for Arg-100.
Crystallographic structure of the nitrogenase iron protein from Azotobacter vinelandii.
Nucleotide-iron-sulfur cluster signal transduction in the nitrogenase iron-protein: the role of Asp125.
The role of metal clusters and MgATP in nitrogenase catalysis.
Molybdenum-independent nitrogenases of Azotobacter vinelandii: a functional species of alternative nitrogenase-3 isolated from a molybdenum-tolerant strain contains an iron-molybdenum cofactor.
X-ray crystal structure of the nitrogenase molybdenum-iron protein from Clostridium pasteurianum at 3.0-A resolution.
Using dysprosium complexes to probe the nitrogenase paramagnetic centers.
The nitrogenase MoFe protein. A secondary structure prediction.
The unusual metal clusters of nitrogenase: structural features revealed by x-ray anomalous diffraction studies of the MoFe protein from Clostridium pasteurianum.
The nitrogenase FeMo-cofactor and P-cluster pair: 2.2 A resolution structures.
Purification and characterization of a FeMo cofactor-deficient MoFe protein.
MgATP-induced conformational changes in the iron protein from Azotobacter vinelandii, as studied by small-angle x-ray scattering.
Identification of a nitrogenase protein-protein interaction site defined by residues 59 through 67 within the Azotobacter vinelandii Fe protein.
Catalytic formation of a nitrogenase iron-sulfur cluster.
Docking of nitrogenase iron- and molybdenum-iron proteins for electron transfer and MgATP hydrolysis: the role of arginine 140 and lysine 143 of the Azotobacter vinelandii iron protein.
Nitrogenase structure and function: a biochemical-genetic perspective.
Role of the MoFe protein alpha-subunit histidine-195 residue in FeMo-cofactor binding and nitrogenase catalysis.
Involvement of the P cluster in intramolecular electron transfer within the nitrogenase MoFe protein.
Proton NMR investigation of the [4Fe--4S]1+ cluster environment of nitrogenase iron protein from Azotobacter vinelandii: defining nucleotide-induced conformational changes.
Nucleotide hydrolysis and protein conformational changes in Azotobacter vinelandii nitrogenase iron protein: defining the function of aspartate 129.
Evidence for a central role of lysine 15 of Azotobacter vinelandii nitrogenase iron protein in nucleotide binding and protein conformational changes.
Isolation of two forms of the nitrogenase VFe protein from Azotobacter vinelandii.
Evidence for electron transfer from the nitrogenase iron protein to the molybdenum-iron protein without MgATP hydrolysis: characterization of a tight protein-protein complex.
Electron transfer from the nitrogenase iron protein to the [8Fe-(7/8)S] clusters of the molybdenum-iron protein.
Oxidative titration of the nitrogenase VFe protein from Azotobacter vinelandii: an example of redox-gated electron flow.
Elucidating the mechanism of nucleotide-dependent changes in the redox potential of the [4Fe-4S] cluster in nitrogenase iron protein: the role of phenylalanine 135.
The [4Fe-4S] cluster domain of the nitrogenase iron protein facilitates conformational changes required for the cooperative binding of two nucleotides.
Elucidation of a MgATP signal transduction pathway in the nitrogenase iron protein: formation of a conformation resembling the MgATP-bound state by protein engineering.
Circular dichroism and x-ray spectroscopies of Azotobacter vinelandii nitrogenase iron protein. MgATP and MgADP induced protein conformational changes affecting the [4Fe-4S] cluster and characterization of a [2Fe-2S] form.
Nitrogenase of Klebsiella pneumoniae: kinetics of formation of the transition-state complex and evidence for an altered conformation of MoFe protein lacking a FeMoco centre.
Changes in the midpoint potentials of the nitrogenase metal centers as a result of iron protein-molybdenum-iron protein complex formation.
Redox-dependent structural changes in the nitrogenase P-cluster.
Structural analysis of the Trichodesmium nitrogenase iron protein: implications for aerobic nitrogen fixation activity.
The first glimpse of a complex of nitrogenase component proteins by solution X-ray scattering: conformation of the electron transfer transition state complex of Klebsiella pneumoniae nitrogenase.
Structure of ADP x AIF4(-)-stabilized nitrogenase complex and its implications for signal transduction.
Catalytic and biophysical properties of a nitrogenase Apo-MoFe protein produced by a nifB-deletion mutant of Azotobacter vinelandii.
Evidence for coupled electron and proton transfer in the [8Fe-7S] cluster of nitrogenase.
Electron transfer in nitrogenase analyzed by Marcus theory: evidence for gating by MgATP.
Redox properties and electron paramagnetic resonance spectroscopy of the transition state complex of Azotobacter vinelandii nitrogenase.
An all-ferrous state of the Fe protein of nitrogenase. Interaction with nucleotides and electron transfer to the MoFe protein.
The role of methionine 156 in cross-subunit nucleotide interactions in the iron protein of nitrogenase.
Characterization of a variant iron protein of nitrogenase that is impaired in its ability to adopt the MgATP-induced conformational change.
Conformational variability in structures of the nitrogenase iron proteins from Azotobacter vinelandii and Clostridium pasteurianum.
Nitrogenase of Azotobacter vinelandii: kinetic analysis of the Fe protein redox cycle.
MgATP-independent hydrogen evolution catalysed by nitrogenase: an explanation for the missing electron(s) in the MgADP-AlF4 transition-state complex.
Spectroscopic evidence for changes in the redox state of the nitrogenase P-cluster during turnover.
Evidence that MgATP accelerates primary electron transfer in a Clostridium pasteurianum Fe protein-Azotobacter vinelandii MoFe protein nitrogenase tight complex.
In vitro biosynthesis of iron-molybdenum cofactor and maturation of the nif-encoded apodinitrogenase. Effect of substitution for NifH with site-specifically altered forms of NifH.
New insights into structure-function relationships in nitrogenase: A 1.6 A resolution X-ray crystallographic study of Klebsiella pneumoniae MoFe-protein.
Construction and characterization of a heterodimeric iron protein: defining roles for adenosine triphosphate in nitrogenase catalysis.
Formation of a tight 1:1 complex of Clostridium pasteurianum Fe protein-Azotobacter vinelandii MoFe protein: evidence for long-range interactions between the Fe protein binding sites during catalytic hydrogen evolution.
Mechanistic interpretation of the dilution effect for Azotobacter vinelandii and Clostridium pasteurianum nitrogenase catalysis.
Insights into nucleotide signal transduction in nitrogenase: structure of an iron protein with MgADP bound.
Modulating the midpoint potential of the [4Fe-4S] cluster of the nitrogenase Fe protein.
Analysis of steady state Fe and MoFe protein interactions during nitrogenase catalysis.
Nitrogenase: standing at the crossroads.
Identification of an Fe protein residue (Glu146) of Azotobacter vinelandii nitrogenase that is specifically involved in FeMo cofactor insertion.
Controlled protonation of iron-molybdenum cofactor by nitrogenase: a structural and theoretical analysis.
Interaction of acetylene and cyanide with the resting state of nitrogenase alpha-96-substituted MoFe proteins.
MgATP-Bound and nucleotide-free structures of a nitrogenase protein complex between the Leu 127 Delta-Fe-protein and the MoFe-protein.
Electron paramagnetic resonance analysis of different Azotobacter vinelandii nitrogenase MoFe-protein conformations generated during enzyme turnover: evidence for S = 3/2 spin states from reduced MoFe-protein intermediates.
Mechanistic features and structure of the nitrogenase alpha-Gln195 MoFe protein.
FeMo cofactor of nitrogenase: a density functional study of states M(N), M(OX), M(R), and M(I).
Crystal structure of the all-ferrous [4Fe-4S]0 form of the nitrogenase iron protein from Azotobacter vinelandii.
Biochemical and structural characterization of the cross-linked complex of nitrogenase: comparison to the ADP-AlF4(-)-stabilized structure.
Metal substitution in the active site of nitrogenase MFe(7)S(9) (M = Mo(4+), V(3+), Fe(3+)).
Synthesis and characterization of sulfur-voided cubanes. Structural analogues for the MoFe(3)S(3) subunit in the nitrogenase cofactor.
Crystallographic analysis of the MoFe protein of nitrogenase from a nifV mutant of Klebsiella pneumoniae identifies citrate as a ligand to the molybdenum of iron molybdenum cofactor (FeMoco).
Accumulation of 99Mo-containing iron-molybdenum cofactor precursors of nitrogenase on NifNE, NifH, and NifX of Azotobacter vinelandii.
Molybdenum nitrogenases: a crystallographic and mechanistic view.
Nitrogenase MoFe-protein at 1.16 A resolution: a central ligand in the FeMo-cofactor.
Structure of a cofactor-deficient nitrogenase MoFe protein.
Electron-transfer chemistry of the iron-molybdenum cofactor of nitrogenase: delocalized and localized reduced states of FeMoco which allow binding of carbon monoxide to iron and molybdenum.
Comparison of iron-molybdenum cofactor-deficient nitrogenase MoFe proteins by X-ray absorption spectroscopy: implications for P-cluster biosynthesis.
Structural and biochemical implications of single amino acid substitutions in the nucleotide-dependent switch regions of the nitrogenase Fe protein from Azotobacter vinelandii.
A conformational mimic of the MgATP-bound "on state" of the nitrogenase iron protein.
Structural basis for the changes in redox potential in the nitrogenase Phe135Trp Fe protein with MgADP Bound.
Nitrogenase complexes: multiple docking sites for a nucleotide switch protein.
Insights into the role of nucleotide-dependent conformational change in nitrogenase catalysis: Structural characterization of the nitrogenase Fe protein Leu127 deletion variant with bound MgATP.
This enzyme is homologous to that from Klebsiella pneumoniae and Azotobacter vinelandii (M00114 in EzCatDB). This enzyme, Nitrogenase, is composed of molybdenum-iron protein component (MoFe protein; component 1) and iron protein (Fe protein; component 2). The Fe protein component (component 2) transfer electrons to another enzyme component, MoFe protein (component 1). The Fe protein component is a homodimer, which binds two MgATP molecules and one [4Fe-4S] cluster on the interface of the dimer. The MoFe protein is a heterotetramer, composed of two alpha subunits and two beta subunits. The alpha subunit binds a cofactor called, FeMoco centre, which is composed of molybdenum, [7Fe-9S], and homocitrate, whereas the interface of the alpha and beta subunits binds a cofactor, called P cluster, that is [8Fe-7S]. This enzyme catalyzes the following reactions: (A) Electron transfer from FMN of flavodoxin or [2Fe-2S] of ferredoxin to the [4Fe-4S] cluster of Fe protein: (X) Binding of MgATP molecules to the Fe proteins induces the conformational change, leading to the reaction (B): (B) Electron transfer from the [4Fe-4S] cluster to the P-cluster([8Fe-7S]): (C) Hydrolysis of two ATP molecules to produce two ADP molecules, leading to the conformational change in disconnection between the Fe protein and MoFe protein, which inhibits the reaction (B) (Fe protein): (D) Electron transfer from the P-cluster([8Fe-7S]) to the FeMoco centre: (E) Hydrogenation (H2 production from 2 H+ ions) at the FeMoco centre: (F) Nitorogenation (NH3 production from N2 and H+ ions) at the FeMoco centre: ### This enzyme catalyzes N2 reduction: N2 + 8 H+ + 8 e- => 2 NH3 + H2 (1) 2 H+ + 2 e- => H2 (2) N2 + 6 H+ + 6 e- => 2 NH3 Thus, the reactions (E) and (F) (or the MoFe protein cycle) consists of eight sequential one-electron steps [reactions, (A)-(D)], each of which corresponds to an Fe protein cycle (see [12], [86]). ### (A) Electron transfer from FMN of flavodoxin or [2Fe-2S] of ferredoxin to the [4Fe-4S] cluster of Fe protein(see [93], [94]): (B) Electron transfer from the [4Fe-4S] cluster to the P-cluster([8Fe-7S]): (B1) Indirect transfer from the [4Fe-4S] cluster to the P-cluster through Cys94 (bound to [4Fe-4S]), Thr110 and Cys106 (bound to P-cluster). (C) Hydrolysis of two ATP molecules to produce two ADP molecules on the Fe protein (see [16], [17], [18], [35], [91]): (C1) The negative charge of gamma-phsohate group is stabilized by the magnesium ion bound to Ser15, and Lysine residues (Lys9, Lys14, Lys40), and mainchain amide group of Gly11. (C2) Either Asp38 or Asp126 from the adjacent subunit acts as a general base to deprotonate and activate the water molecule. However, this water is not bound to the magnesium ion. (C3) The activated water molecule makes a nucleophilic attack on the phosphorus atom of the gamma-phosphate. (C4) The transition-state must be stabilized by the above stabilizer residues and cofactor. (C5) The reaction completes. (D) Electron transfer from the P-cluster([8Fe-7S]) to the FeMoco centre (see [20], [33], [74]): (D1) Indirect transfer from the the P-cluster to the FeMoco centre through Cys53 (bound to P-cluster), Gln182 (bound to homocitrate), and homocitrate itself (bound to FeMoco). (E) Hydrogenation (H2 production from 2 H+ ions) at the FeMoco centre (see [20], [73]): (F) Nitorogenation (NH3 production from N2 and H+ ions) at the FeMoco centre (see [24], [87], [89]):