Disease relevance of Azotobacter

• We studied the effects of different concentrations of Mn2+ and Mg2+ on assimilatory NO3- reduction and NH4+ assimilation in cultures of two microorganisms commonly found in soil [Pseudomonas fluorescens (ATCC 13525) and Azotobacter chroococcum (ATCC 9043)] and in an enrichment culture of soil microorganisms [1].
• The core extrusion method has been applied to the determination of the type ([2Fe-2S], [4Fe-4S]) and number of iron-sulfur centers in the FeMo proteins of the nitrogenases from Clostridium pasteurianum and Azotobacter vinelandii [2].
• In this paper, I report the purification of a protein from Escherichia coli that is very similar in sequence, molecular weight, and the reactions it can catalyze to the protein encoded by the Azotobacter vinelandii nifS gene [3].
• These are typified by the 3Fe centers in aconitase, Desulfovibrio gigas FdII, and Azotobacter crooccocum Fd [4].
• The structures of Azotobacter vinelandii ferredoxin I (AvFdI) and Peptococcus aerogenes ferredoxin (PaFd), near their analogous [4e-4S]2+/+ clusters, are highly conserved (Backes, G., Mino, Y., Loehr, T.M., Meyer, T.E., Cusanovich, M.A., Sweeney, W.V., Adman, E.T., and Sanders-Loehr, J. (1991) J. Am. Chem. Soc. 11, 2055-2064) [5].

High impact information on Azotobacter

• In Azotobacter vinelandii ferredoxin I, reduction of a buried iron-sulphur cluster draws in a solvent proton, whereas re-oxidation is 'gated' by proton release to the solvent [6].
• Structures recently proposed for the FeMo-cofactor and P-cluster pair of the nitrogenase molybdenum-iron (MoFe)-protein from Azotobacter vinelandii have been crystallographically verified at 2.2 angstrom resolution [7].
• Structural genes for the vanadium nitrogenase from Azotobacter chroococcum [8].
• Regulation of nitrogen metabolism in Azotobacter vinelandii: isolation of ntr and glnA genes and construction of ntr mutants [9].
• Second gene (nifH*) coding for a nitrogenase iron protein in Azotobacter chroococcum is adjacent to a gene coding for a ferredoxin-like protein [10].

Chemical compound and disease context of Azotobacter

• The biosynthesis of the FeMo cofactor (FeMoco) of Azotobacter vinelandii nitrogenase presumably starts with the production of its Fe/S core by NifB (the nifB gene product) [11].
• Azotobacter vinelandii ferredoxin I is a small protein that contains one [4Fe-4S] cluster and one [3Fe-4S] cluster [12].
• The MoFe protein from Azotobacter vinelandii catalyzes the reduction of methylene blue and other oxidants by H2 under anaerobic conditions [13].
• Spectroscopic studies of ferricyanide oxidation of Azotobacter vinelandii ferredoxin I [14].
• A molybdenum-iron cluster (Mo-Fe cluster) containing 6 Fe atoms per Mo was isolated by methyl ethyl ketone extraction of component I of nitrogenase from Azotobacter vinelandii [15].

Biological context of Azotobacter

• The NIFL regulatory protein controls transcriptional activation of nitrogen fixation (nif) genes in Azotobacter vinelandii by direct interaction with the enhancer binding protein NIFA [16].
• Nitrogen fixation by Azotobacter vinelandii in tungsten-containing medium [17].
• Alteration of aspartate 39 to asparagine (D39N) in the nucleotide binding site of Azotobacter vinelandii Fe protein by site-directed mutagenesis resulted in an Fe protein-MoFe protein complex that did not dissociate after electron transfer [18].
• Structure of Azotobacter vinelandii 7Fe ferredoxin. Amino acid sequence and electron density maps of residues [19].
• The Azotobacter vinelandii genome encodes a family of seven secreted Ca(2+)-dependent epimerases (AlgE1--7) catalyzing the polymer level epimerization of beta-D-mannuronic acid (M) to alpha-L-guluronic acid (G) in the commercially important polysaccharide alginate [20].

Anatomical context of Azotobacter

• Chlorpromazine inhibition of electron transport in Azotobacter vinelandii membranes [21].

Gene context of Azotobacter

• Selenocysteine lyase (EC 4.4.1.16) exclusively decomposes selenocysteine to alanine and elemental selenium, whereas cysteine desulfurase (NIFS protein) of Azotobacter vinelandii acts indiscriminately on both cysteine and selenocysteine to produce elemental sulfur and selenium respectively, and alanine [22].
• Crystallographic and enzymatic investigations on the role of Ser558, His610, and Asn614 in the catalytic mechanism of Azotobacter vinelandii dihydrolipoamide acetyltransferase (E2p) [23].
• The amn gene was expressed in AMP nucleosidase deficient strains of Azotobacter vinelandii and E. coli [24].
• Mobile sequences in the pyruvate dehydrogenase complex, the E2 component, the catalytic domain and the 2-oxoglutarate dehydrogenase complex of Azotobacter vinelandii, as detected by 600 MHz 1H-NMR spectroscopy [25].
• The Azotobacter chroococcum hydrogenase gene cluster: sequences and genetic analysis of four accessory genes, hupA, hupB, hupY and hupC [26].

Analytical, diagnostic and therapeutic context of Azotobacter

• Site-directed mutagenesis of Azotobacter vinelandii ferredoxin I: [Fe-S] cluster-driven protein rearrangement [12].
• The Fe(CN)3-(6) oxidation of the crystallographically characterized [[3Fe-3S], [4Fe-4S]] ferredoxin I of Azotobacter vinelandii has been studied using absorption, circular dichroism, magnetic circular dichroism, and EPR spectroscopies [14].
• 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 [27].
• The Mo-Fe protein of Azotobacter vinelandii nitrogenase was fractionated on 9.5 M urea isoelectric focusing gels and gave three distinct bands (alpha', alpha", beta') [28].
• The structural and magnetic properties of the iron-cores of reconstituted horse spleen ferritin and Azotobacter vinelandii bacterioferritin have been investigated by high-resolution transmission electron microscopy, electron diffraction and Mossbauer spectroscopy [29].

References