scholarly journals Characterization of Anammox Hydrazine Dehydrogenase, a Key N2-producing Enzyme in the Global Nitrogen Cycle

2016 ◽  
Vol 291 (33) ◽  
pp. 17077-17092 ◽  
Author(s):  
Wouter J. Maalcke ◽  
Joachim Reimann ◽  
Simon de Vries ◽  
Julea N. Butt ◽  
Andreas Dietl ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Structural Changes ◽  
Catalytic Properties ◽  
Anammox Bacteria ◽  
Sequence Analyses ◽  
Denitrifying Microorganisms ◽  
Global Nitrogen Cycle

Anaerobic ammonium-oxidizing (anammox) bacteria derive their energy for growth from the oxidation of ammonium with nitrite as the electron acceptor. N2, the end product of this metabolism, is produced from the oxidation of the intermediate, hydrazine (N2H4). Previously, we identified N2-producing hydrazine dehydrogenase (KsHDH) from the anammox organism Kuenenia stuttgartiensis as the gene product of kustc0694 and determined some of its catalytic properties. In the genome of K. stuttgartiensis, kustc0694 is one of 10 paralogs related to octaheme hydroxylamine (NH2OH) oxidoreductase (HAO). Here, we characterized KsHDH as a covalently cross-linked homotrimeric octaheme protein as found for HAO and HAO-related hydroxylamine-oxidizing enzyme kustc1061 from K. stuttgartiensis. Interestingly, the HDH trimers formed octamers in solution, each octamer harboring an amazing 192 c-type heme moieties. Whereas HAO and kustc1061 are capable of hydrazine oxidation as well, KsHDH was highly specific for this activity. To understand this specificity, we performed detailed amino acid sequence analyses and investigated the catalytic and spectroscopic (electronic absorbance, EPR) properties of KsHDH in comparison with the well defined HAO and kustc1061. We conclude that HDH specificity is most likely derived from structural changes around the catalytic heme 4 (P460) and of the electron-wiring circuit comprising seven His/His-ligated c-type hemes in each subunit. These nuances make HDH a globally prominent N2-producing enzyme, next to nitrous oxide (N2O) reductase from denitrifying microorganisms.

scholarly journals Characterization of TEM-56, a Novel β-Lactamase Produced by a Klebsiella pneumoniae Clinical Isolate

2000 ◽  
Vol 44 (2) ◽  
pp. 453-455 ◽  
Author(s):  
Catherine Neuwirth ◽  
Roger Labia ◽  
Eliane Siebor ◽  
Andre Pechinot ◽  
Stephanie Madec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Amino Acid Sequence ◽  
Clinical Isolate ◽  
Isoelectric Point ◽  
Catalytic Properties ◽  
Resistance Level ◽  
Extended Spectrum ◽  
Moderate Resistance

ABSTRACT TEM-56 produced by a Klebsiella pneumoniae clinical isolate is a novel β-lactamase of isoelectric point 6.4 that confers a moderate resistance level to expanded-spectrum cephalosporins. The amino acid sequence deduced from the corresponding bla gene showed two amino acid replacements with respect to the TEM-2 sequence: Glu-104 to Lys and His-153 to Arg. This enzyme showed catalytic properties close to those of TEM-18. Thus, TEM-56 appears as a new TEM mutant, an intermediary between TEM-18 and the extended-spectrum β-lactamase TEM-21.

scholarly journals Amino acid sequence and characterization of a protein inhibitor of protein kinase C.

1990 ◽  
Vol 265 (8) ◽  
pp. 4583-4591 ◽  
Author(s):  
J D Pearson ◽  
D B DeWald ◽  
W R Mathews ◽  
N M Mozier ◽  
H A Zürcher-Neely ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Amino Acid ◽  
Protein Kinase ◽  
Amino Acid Sequence ◽  
Protein Inhibitor ◽  
Kinase C

scholarly journals Purification and partial characterization of a lectin from Caesalpinia tinctoria Domb, ex Dc fruits

2003 ◽  
Vol 15 (2) ◽  
pp. 119-122 ◽  
Author(s):  
Marli Lourdes de Oliveira ◽  
Leila Maria Beltramini ◽  
Salvatore Giovanni de Simone ◽  
Maria Helena Nasser Brumano ◽  
Rosemeire Aparecida Silva-Lucca ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Terminal Amino Acid ◽  
Saline Extract ◽  
Hydrophobic Residues ◽  
Terminal Amino ◽  
Helix Conformation ◽  
Far Ultraviolet ◽  
Terminal Amino Acid Sequence

A lectin was isolated from the pod saline extract of Caesalpinia tinctoria by dialoconcentration on Centripep-10 and affinity chromatography on chitin column. The purified lectin was partially characterized with respect to its biochemical and structural properties. It contains 8.3 % of carbohydrate and exhibited an agglutinating activity against human erythrocytes (ABO groups). Its amino acid composition was characterized by a great number of acidic and hydrophobic residues and the estimated molecular mass was 12.5 kDa. The presence of only one N-terminal amino acid sequence (D¹-V-P-A-Y-V-Y-V-H-F10-G-F-G-E-E-H-R -D-V-F20-D), showed the homogeneity of the purified lectin. The far-ultraviolet circular dichroism (CD) spectrum of lectin indicated that it contains 10 % a-helix, 38 % b-sheet, 28 % unordered form and 6 % of P II (poly-L-proline II helix conformation).

scholarly journals The VP7 Genes of Two G9 Rotaviruses Isolated in 1980 from Diarrheal Stool Samples Collected in Washington, DC, Are Unique Molecularly and Serotypically

2008 ◽  
Vol 82 (8) ◽  
pp. 4175-4179 ◽  
Author(s):  
Dianjun Cao ◽  
Norma Santos ◽  
Ronald W. Jones ◽  
Masatoshi Tatsumi ◽  
Jon R. Gentsch ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Medical Center ◽  
Washington Dc ◽  
Sequence Analyses ◽  
National Medical ◽  
Lineage 2 ◽  
Stool Samples ◽  
Vp7 Gene

ABSTRACT In a retrospective study of archival diarrheal stool samples collected from 1974 to 1991 at Children's Hospital National Medical Center, Washington, DC, we detected three genotype G9P[8] viruses in specimens collected in 1980, which represented the earliest human G9 viruses ever isolated. The VP7 genes of two culture-adapted 1980 G9 viruses were phylogenetically related closely to the lineage 2 G9 virus VP7 gene. Unexpectedly, however, the VP7s of the 1980 G9 viruses were more closely related serotypically to lineage 3 VP7s than to lineage 2 VP7, which may be supported by amino acid sequence analyses of the VP7 proteins.

scholarly journals Characterization of two newly isolated Staphylococcus aureus bacteriophages from Japan belonging to the genus Silviavirus

2020 ◽  
Vol 165 (10) ◽  
pp. 2355-2359
Author(s):  
Naoya Kitamura ◽  
Eri Sasabe ◽  
Shigenobu Matsuzaki ◽  
Masanori Daibata ◽  
Tetsuya Yamamoto
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dna Sequences ◽  
Related Gene ◽  
Bacteriophage Therapy ◽  
Dna Rearrangements ◽  
Site Specific

Abstract Two Staphylococcus aureus bacteriophages, KSAP7 and KSAP11, were isolated from sewage and characterized. Based on morphology and DNA sequences, they were assigned to the genus Silviavirus, subfamily Twortvirinae, family Herelleviridae, whose members are hypothesized to be suitable for bacteriophage therapy. The KSAP7 and KSAP11 genomes were 137,950 and 138,307 bp in size, respectively. Although their DNA sequences were almost identical, evidence of site-specific DNA rearrangements was found in two regions. Changes in the number of PIEPEK amino acid sequence repeats encoded by orf10 and the insertion/deletion of a 541-bp sequence that includes a possible tail-related gene were identified.

scholarly journals Biochemical characterization of a second family of human Ia molecules, HLA-DS, equivalent to murine I-A subregion molecules.

1982 ◽  
Vol 156 (2) ◽  
pp. 550-566 ◽  
Author(s):  
S M Goyert ◽  
J E Shively ◽  
J Silver
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequence Identity ◽  
Biochemical Characterization ◽  
Amino Acid Sequence Homology ◽  
Molecular Weights ◽  
Hla Dr ◽  
D Region ◽  
Polypeptide Chains

In mice, two families of structurally distinct Ia molecules, one designated I-A and the other I-E, have been identified and characterized. The HLA-DR molecules represent one family of human Ia molecules equivalent to the murine I-E molecules on the basis of amino acid sequence homology. We describe the isolation and biochemical characterization of a second family of human Ia molecules, designated HLA-DS for second D-region locus, equivalent to the murine I-A molecules. The human HLA-DS molecules consist of two polypeptide chains, DS alpha (37,000 mol wt) and DS beta (29,000 mol wt), with 73% amino acid sequence identity to the murine I-A molecules. Furthermore, the HLA-DS molecules are closely linked genetically to HLA-DR molecules, a situation analogous to that observed in mice. The similarity in molecular weights of the DR and DS molecules might explain why others have failed to identify the latter in man.

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