scholarly journals Electron transfer to nitrogenase. Characterization of flavodoxin from Azotobacter chroococcum and comparison of its redox potentials with those of flavodoxins from Azotobacter vinelandii and Klebsiella pneumoniae (nifF-gene product)

1986 ◽  
Vol 239 (1) ◽  
pp. 69-75 ◽  
Author(s):  
J Deistung ◽  
R N F Thorneley
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Gene Product ◽  
Azotobacter Vinelandii ◽  
Azotobacter Chroococcum ◽  
Amino Acid Sequences ◽  
Published Data ◽  
Redox Potentials ◽  
Hydrogen Electrode ◽  
Visible Spectra

Flavodoxin in the hydroquinone state acts as an electron donor to nitrogenase in several nitrogen-fixing organisms. The mid-point potentials for the oxidized-semiquinone and semiquinone-hydroquinone couples of flavodoxins isolated from facultative anaerobe Klebsiella pneumoniae (nifF-gene product, KpFld) and the obligate aerobe Azotobacter chroococcum (AcFld) were determined as a function of pH. The mid-point potentials of the semiquinone-hydroquinone couples of KpFld and AcFld are essentially independent of pH over the range pH 7-9, being -422 mV and -522 mV (normal hydrogen electrode) at pH 7.5 respectively. The mid-point potentials of the quinone-semiquinone couples at pH 7.5 are -200 mV (KpFld) and -133 mV (AcFld) with delta Em/pH of -65 +/- 4 mV (KpFld) and -55 +/- 2 mV (AcFld) over the range pH 7.0-9.5. This indicates that reduction of the quinone is coupled to protonation to yield a neutral semiquinone. The significance of these values with respect to electron transport to nitrogenase is discussed. The amino acid compositions, the N- and C-terminal amino acid sequences and the u.v.-visible spectra of KpFld and AcFld were determined and are compared with published data for flavodoxins isolated from Azotobacter vinelandii.

Identification of genes unique to Mo-independent nitrogenase systems in diverse diazotrophs

1999 ◽  
Vol 45 (4) ◽  
pp. 312-317 ◽  
Author(s):  
Telisa M Loveless ◽  
Paul E Bishop
Keyword(s):  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Gene Product ◽  
Rhodospirillum Rubrum ◽  
Azotobacter Vinelandii ◽  
Amino Acid Sequences ◽  
Nitrogen Fixing Bacteria ◽  
Distinct Cluster ◽  
Genomic Dnas ◽  
Product Forms

A number of nitrogen-fixing bacteria were screened using PCR for genes (vnfG and anfG) unique to the V-containing nitrogenase (vnf) and the Fe-only nitrogenase (anf) systems. Products with sequences similar to that of vnfG were obtained from Azotobacter paspali and Azotobacter salinestris genomic DNAs, and products with sequences similar to that of anfG were obtained from Azomonas macrocytogenes, Rhodospirillum rubrum, and Azotobacter paspali DNAs. Phylogenetic analysis of the deduced amino acid sequences of anfG and vnfG genes shows that each gene product forms a distinct cluster. Furthermore, amplification of an internal 839-bp region in anfD and vnfD yielded a product similar to anfD from Heliobacterium gestii and a product similar to vnfD from Azotobacter paspali and Azotobacter salinestris. Phylogenetic analysis of NifD, VnfD, and AnfD amino acid sequences indicates that AnfD and VnfD sequences are more closely related to each other than either is to NifD. The results of this study suggest that Azotobacter salinestris possesses the potential to express the vanadium (V)-containing nitrogenase (nitrogenase 2) and that R. rubrum, Azomonas macrocytogenes, and H. gestii possess the potential to express the Fe-only nitrogenase (nitrogenase 3). Like Azotobacter vinelandii, Azotobacter paspali appears to have the potential to express both the V-containing nitrogenase and the Fe-only nitrogenase.Key words: Mo-independent nitrogenase systems, diverse diazotrophs, vnfG, anfG.

Corticosteroid Catabolism by Klebsiella pneumoniae as a Possible Mechanism for Increased Pneumonia Risk

2019 ◽  
Vol 20 (4) ◽  
pp. 309-316 ◽  
Author(s):  
Pritam Chattopadhyay ◽  
Goutam Banerjee
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Kegg Pathway ◽  
Degradation Pathway ◽  
Amino Acid Sequences ◽  
Biological Mechanism ◽  
Clinical Strains ◽  
Catabolism Pathway ◽  
Steroid Catabolism ◽  
Nutrition Source

Background: Several strains of Klebsiella pneumoniae are responsible for causing pneumonia in lung and thereby causing death in immune-suppressed patients. In recent year, few investigations have reported the enhancement of K. pneumoniae population in patients using corticosteroid containing inhaler. Objectives: The biological mechanism(s) behind this increased incidence has not been elucidated. Therefore, the objective of this investigating was to explore the relation between Klebsiella pneumoniae and increment in carbapenamase producing Enterobacteriaceae score (ICS). Methods: The available genomes of K. pneumoniae and the amino acid sequences of steroid catabolism pathway enzymes were taken from NCBI database and KEGG pathway tagged with UniPort database, respectively. We have used different BLAST algorithms (tBLASTn, BLASTp, psiBLAST, and delBLAST) to identify enzymes (by their amino acid sequence) involved in steroid catabolism. Results: A total of 13 enzymes (taken from different bacterial candidates) responsible for corticosteroid degradation have been identified in the genome of K. pneumoniae. Finally, 8 enzymes (K. pneumoniae specific) were detected in four clinical strains of K. pneumoniae. This investigation intimates that this ability to catabolize corticosteroids could potentially be one mechanism behind the increased pneumonia incidence. Conclusion: The presence of corticosteroid catabolism enzymes in K. pneumoniae enhances the ability to utilize corticosteroid for their own nutrition source. This is the first report to demonstrate the corticosteroid degradation pathway in clinical strains of K. pneumoniae.

scholarly journals The molybdenum–iron protein of Klebsiella pneumoniae nitrogenase. Evidence for non-identical subunits from peptide ‘mapping’

1976 ◽  
Vol 155 (2) ◽  
pp. 383-389 ◽  
Author(s):  
C Kennedy ◽  
R R. Eady ◽  
E Kondorosi ◽  
D K Rekosh
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Sodium Dodecyl Sulphate ◽  
Azotobacter Vinelandii ◽  
Peptide Mapping ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Amino Acid Content ◽  
Rhizobium Japonicum ◽  
Fe Protein

The molybdenum- and iron-containing protein components of nitrogenase purified from Klebsiella pneumoniae, Azotobacter vinelandii, Azotobacter chroococcum and Rhizobium japonicum bacteroids all gave either one or two protein-staining bands after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, depending on the commercial brand of sodium dodecyl sulphate used. The single band obtained with K. pneumoniae Mo-Fe protein when some commercial brands of sodium dodecyl sulphate were used in the preparation of the electrode buffer was resolved into two bands by the addition of 0.01% (v/v) dodecanol to the buffer. Protein extracted from the two bands obtained after electrophoresis of K. pneumoniae Mo-Fe protein gave unique and distinct peptide ‘maps’ after tryptic digestion. Undissociated Mo-Fe protein contained both sets of tryptic peptides. These data are consistent with Mo-Fe protein from K. pneumoniae being composed of non-identical subunits. Amino acid analyses of the subunit proteins revealed some clear differences in amino acid content, but the two subunits showed close compositional relatedness, with a different index [Metzer, H., Shapiro, M.B., Mosiman, J.E. & Vinton, J.G. (1968) Nature (London) 219, 1166-1168] of 4.7.

scholarly journals The melanoma antigen gp75 is the human homologue of the mouse b (brown) locus gene product.

1990 ◽  
Vol 171 (4) ◽  
pp. 1375-1380 ◽  
Author(s):  
S Vijayasaradhi ◽  
B Bouchard ◽  
A N Houghton
Keyword(s):  
Amino Acid ◽  
Metastatic Melanoma ◽  
Gene Product ◽  
Coat Color ◽  
Immunological Tolerance ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Igg Antibodies ◽  
Human Homologue ◽  
Melanoma Antigen

The gp75 antigen is an abundant intracellular glycoprotein expressed in melanosomes of human pigmented melanocytes and melanomas. IgG antibodies in sera of a patient with metastatic melanoma have been shown to immunoprecipitate gp75, suggesting that immunological tolerance against gp75 can be broken. The mouse mAb TA99, which specifically recognizes gp75, was used to isolate and purify the antigen. Amino acid sequences of three internal peptides were determined from the purified gp75 polypeptide. cDNA clones were isolated by screening with oligonucleotides based on these peptide sequences. The gp75 peptides and cDNA had approximately 90% identity with, respectively, the derived amino acid and nucleotide sequences of a mouse gene that maps to the b (brown) locus. The brown locus determines coat color in the mouse, suggesting that gp75 regulates or influences the type of melanin synthesized.

scholarly journals Amino acid sequences around the cystine residues in horse growth hormone

1968 ◽  
Vol 109 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Louise Oliver ◽  
Anne Stockell Hartree
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Amino Acid ◽  
Growth Hormones ◽  
Amino Acid Sequences ◽  
The Other ◽  
Published Data ◽  
C Terminus

The cystine-containing peptides of horse growth hormone were isolated and their amino acid sequences determined. Four unique half-cystine residues occur in two peptides, one containing 11 and the other, at the C-terminus of the protein, 15 amino acids. These sequences are compared with published data on growth hormones from other species.

scholarly journals Alteration of GyrA Amino Acid Required for Ciprofloxacin Resistance in Klebsiella pneumoniae Isolates in China

2008 ◽  
Vol 52 (8) ◽  
pp. 2980-2983 ◽  
Author(s):  
Yingmei Fu ◽  
Lishuang Guo ◽  
Yan Xu ◽  
Wenli Zhang ◽  
Jiaao Gu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Published Data ◽  
Ciprofloxacin Resistance ◽  
Single Substitution

ABSTRACT Resistance to ciprofloxacin was detected in 111 (48.1%) isolates of Klebsiella pneumoniae from China. GyrA alterations were identified in the ciprofloxacin-resistant and ciprofloxacin-susceptible isolates. The results, including previously published data, indicate that the single substitution Ser83→Ile and three types of double mutations at Ser83 and Asp87 were required for ciprofloxacin resistance (P < 0.05).

scholarly journals Novel Plasmid-Encoded Class C β-Lactamase (MOX-2) in Klebsiella pneumoniae from Greece

2002 ◽  
Vol 46 (7) ◽  
pp. 2262-2265 ◽  
Author(s):  
Laurent Raskine ◽  
Isabelle Borrel ◽  
Guilène Barnaud ◽  
Sophie Boyer ◽  
Béatrice Hanau-Berçot ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Hydrolytic Activity ◽  
Amino Acid Sequences ◽  
Clinical Strain ◽  
Aeromonas Sobria ◽  
Class C

ABSTRACT Klebsiella pneumoniae KOL, a clinical strain resistant to various β-lactams, was isolated from the stools of a patient from Greece. This strain harbored a new pI 9.1 plasmid-mediated AmpC β-lactamase with unusually high levels of hydrolytic activity for cefoxitin and cefotetan that we named MOX-2. Sequencing of bla MOX-2 revealed 93.2, 92.9, 92.7, and 73.1% identities with the deduced amino acid sequences of CMY-8, MOX-1, CMY-1, and the AmpC β-lactamase of Aeromonas sobria, respectively.

scholarly journals Structural studies on Desulfovibrio gigas cytochrome c3 by two-dimensional 1H-nuclear-magnetic-resonance spectroscopy

1993 ◽  
Vol 294 (3) ◽  
pp. 909-915 ◽  
Author(s):  
M A Piçarra-Pereira ◽  
D L Turner ◽  
J LeGall ◽  
A V Xavier
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Reduced Form ◽  
Desulfovibrio Vulgaris ◽  
Resonance Spectroscopy ◽  
Two Dimensional ◽  
Redox Potentials ◽  
Cytochrome C3 ◽  
X Ray ◽  
Desulfovibrio Gigas

Several aromatic amino acid residues and haem resonances in the fully reduced form of Desulfovibrio gigas cytochrome c3 are assigned, using two-dimensional 1H n.m.r., on the basis of the interactions between the protons of the aromatic amino acids and the haem protons as well as the intrahaem distances known from the X-ray structure [Kissinger (1989) Ph.D. Thesis, Washington State University]. The interhaem interactions observed in the n.m.r. spectra are in full agreement with the D. gigas X-ray structure and also with the n.m.r. data from Desulfovibrio vulgaris (Hildenborough) [Turner, Salgueiro, LeGall and Xavier (1992) Eur. J. Biochem. 210, 931-936]. The good correlation between the calculated ring-current shifts and the observed chemical shifts strongly supports the present assignments. Observation of the two-dimensional nuclear-Overhauser-enhancement spectra of the protein in the reduced, intermediate and fully oxidized stages led to the ordering of the haems in terms of their midpoint redox potentials and their identification in the X-ray structure. The first haem to oxidize is haem I, followed by haems II, III and IV, numbered according to the Cys ligand positions in the amino acid sequences [Mathews (1985) Prog. Biophys. Mol. Biol. 54, 1-56]. Although the haem core architecture is the same for the different Desulfovibrio cytochromes c3, the order of redox potentials is different.

scholarly journals A Mössbauer spectroscopic investigation of the redox behaviour of the molybdenum-iron protein from Klebsiella pneumoniae nitrogenase. Mechanistic and structural implications

1980 ◽  
Vol 191 (2) ◽  
pp. 449-455 ◽  
Author(s):  
B E Smith ◽  
M J O'Donnell ◽  
G Lang ◽  
K Spartalian
Keyword(s):  
Klebsiella Pneumoniae ◽  
Redox Properties ◽  
Redox Process ◽  
Published Data ◽  
Hydrogen Electrode ◽  
Molybdenum Iron Protein ◽  
Iron Protein ◽  
Fe Protein ◽  
Enzyme Turnover ◽  
Mössbauer Parameters

The redox properties of the nitrogenase Mo-Fe protein from Klebsiella pneumoniae have been monitored by 57Fe Mössbauer spectroscopy between -460 and -160mV (relative to the normal hydrogen electrode). Two redox processes associated with the atoms of the protein were observed. One at -216mV (pH 8.7) was associated with the Fe-Mo cofactor centres in the protein and allowed identification of the Mössbauer parameters of the oxidized form of these centres. The other redox process at -340mV (pH 8.7) was associated with species M5 [Smith & Lang (1974) Biochem. J. 137, 169-180]. This latter redox process may be involved in enzyme turnover. The oxidized form of species M5 interacts magnetically with species M4. The structural implications of the data have been considered in relation to other published data. It is concluded that an unequivocal assignment of the M4 and M5 atoms to Fe-S cluster types is not yet possible.

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