Hup
Mostrando 13-24 de 121 artigos, teses e dissertações.
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13. Uptake Hydrogenase (Hup) in Common Bean (Phaseolus vulgaris) Symbioses
Strains of Rhizobium forming nitrogen-fixing symbioses with common bean were systematically examined for the presence of the uptake hydrogenase (hup) structural genes and expression of uptake hydrogenase (Hup) activity. DNA with homology to the hup structural genes of Bradyrhizobium japonicum was present in 100 of 248 strains examined. EcoRI fragments with m
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14. Evidence for a Third Uptake Hydrogenase Phenotype among the Soybean Bradyrhizobia
The existence of a hydrogen uptake host-regulated (Hup-hr) phenotype was established among the soybean bradyrhizobia. The Hup-hr phenotype is characterized by the expression of uptake hydrogenase activity in symbiosis with cowpea but not soybean. Uptake hydrogenase induction is not possible under free-living cultural conditions by using techniques developed
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15. Inhibition of cell division in hupA hupB mutant bacteria lacking HU protein.
Escherichia coli hupA hypB double mutants that lack HU protein have severe cellular defects in cell division, DNA folding, and DNA partitioning. Here we show that the sfiA11 mutation, which alters the SfiA cell division inhibitor, reduces filamentation and production of anucleate cells in AB1157 hupA hupB strains. However, lexA3(Ind-) and sfiB(ftsZ)114 mutat
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16. Subcellular localization of the inducible Chlorella HUP1 monosaccharide-H+ symporter and cloning of a Co-induced galactose-H+ symporter.
The unicellular green alga Chlorella kessleri can induce monosaccharide-H+ symport catalyzing the energy-dependent transport of D-glucose (D-Glc) and several other pentoses and hexoses across the plasmalemma. The gene coding for the inducible HUP1 monosaccharide-H+ symporter has been cloned and the protein has been characterized previously. The data presente
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17. Bacterial genes involved in incorporation of nickel into a hydrogenase enzyme.
Nickel is an essential component of all H2-uptake hydrogenases. A fragment of DNA that complements a H2-uptake-deficient but nickel-cured mutant strain (JHK7) of Bradyrhizobium japonicum was isolated and sequenced. This 4.5-kb DNA fragment contains four open reading frames designated as ORF1, hupN, hupO, and hupP, which encode polypeptides with predicted mas
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18. Genetic organization of the hydrogen uptake (hup) cluster from Rhizobium leguminosarum.
In symbiosis with peas, Rhizobium leguminosarum UPM791 induces the synthesis of a hydrogen uptake (Hup) system that recycles hydrogen generated in nodules by nitrogenase. A cosmid (pAL618) containing hup genes from this strain on a 20-kilobase-pair (kb) DNA insert has previously been isolated in our laboratory (A. Leyva, J. M. Palacios, T. Mozo, and T.Ruiz-A
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19. Sequence analysis and interposon mutagenesis of the hupT gene, which encodes a sensor protein involved in repression of hydrogenase synthesis in Rhodobacter capsulatus.
The hupT gene, which represses hydrogenase gene expression in the purple photosynthetic bacterium Rhodobacter capsulatus, has been identified and sequenced. The nucleotide sequence of hupT and of the contiguous downstream open reading frame, hupU, is reported. The HupT protein of 456 amino acids (48,414 Da) has sequence similarity with the FixL, DctB, NtrB,
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20. Diversity and Evolution of Hydrogenase Systems in Rhizobia
Uptake hydrogenases allow rhizobia to recycle the hydrogen generated in the nitrogen fixation process within the legume nodule. Hydrogenase (hup) systems in Bradyrhizobium japonicum and Rhizobium leguminosarum bv. viciae show highly conserved sequence and gene organization, but important differences exist in regulation and in the presence of specific genes.
American Society for Microbiology.
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21. Identification and Characterization of hupT, a Gene Involved in Negative Regulation of Hydrogen Oxidation in Bradyrhizobium japonicum
The Bradyrhizobium japonicum hupT gene was sequenced, and its gene product was found to be homologous to NtrB-like histidine kinases. A hupT mutant expresses higher levels of hydrogenase activity than the wild-type strain under hydrogenase-inducing conditions (i.e., microaerobiosis plus hydrogen, or symbiosis), whereas in noninduced hupT cells, hupSL express
American Society for Microbiology.
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22. Comparison of Hup Trait and Intrinsic Antibiotic Resistance for Assessing Rhizobial Competitiveness Axenically and in Soil
The competitiveness of dual-strain inocula of cowpea rhizobia for nodulation of Vigna unguiculata (L.) Walp. was studied axenically between one slow-growing strain (P132, HP147, 401, or 22A1) and one fast-growing strain (176A26 or 176A28) at logarithmic inoculum ratios ranging from 103 to 10−3. Nodule infectivity was determined by multiple intrinsic antibi
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23. Characterization of the Hydrogen-Deuterium Exchange Activities of the Energy-Transducing HupSL Hydrogenase and H2-Signaling HupUV Hydrogenase in Rhodobacter capsulatus
Rhodobacter capsulatus synthesizes two homologous protein complexes capable of activating molecular H2, a membrane-bound [NiFe] hydrogenase (HupSL) linked to the respiratory chain, and an H2 sensor encoded by the hupUV genes. The activities of hydrogen-deuterium (H-D) exchange catalyzed by the hupSL-encoded and the hupUV-encoded enzymes in the presence of D2
American Society for Microbiology.
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24. Transposon Tn5-Generated Bradyrhizobium japonicum Mutants Unable To Grow Chemoautotrophically with H2
Twelve Tn5-induced mutants of Bradyrhizobium japonicum unable to grow chemoautotrophically with CO2 and H2 (Aut−) were isolated. Five Aut− mutants lacked hydrogen uptake activity (Hup−). The other seven Aut− mutants possessed wild-type levels of hydrogen uptake activity (Hup+), both in free-living culture and symbiotically. Three of the Hup− mutant