Physiology, Biochemistry, and Genetics of the Uptake Hydrogenase in Rhizobia

Evans, Harold J.; Harker, Alan R.; Papen, H.; Russell, Sterling A.; Hanus, F. J.; Zuber, Mohammed

doi:10.1146/annurev.mi.41.100187.002003

Cited by 119 publications

(38 citation statements)

References 45 publications

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“…The major physiological reaction of the membrane-bound hydrogenases of Rhizobia and the photosynthetic bacteria is hydrogen consumption [52,531 and similarly, while Desulfovibrio is capable of hydrogen production, the periplasmic hydrogenases of these organisms are more usually involved in the uptake of hydrogen as a source of electrons to support sulphate reduction [54]. In contrast, recent evidence points to a role in reductant disposal (i.e.…”

Section: Discussionmentioning

confidence: 99%

Soluble hydrogenase of Anabaena cylindrica

Ewart

Reed

Smith

1990

European Journal of Biochemistry

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A gene potentially encoding a subunit of the soluble hydrogenase of Anabaena cylindrica was isolated from a genomic library by screening with a set of redundant oligonucleotides, the sequence of which was deduced from the amino acid sequence of the purified hydrogenase subunit that catalyses tritium exchange. The nucleotide sequence of the potential gene was determined from two overlapping DNA fragments spanning 7237 bp of the A . cylindrica genome. The region sequenced contained an open reading frame encoding a protein of 383 amino acids with a predicted molecular mass of 41 108 Da. The NH,-terminal amino acid sequence of the purified enzyme, determined by Edman degradation, corresponds exactly with that deduced from the nucleic acid sequence.No significant amino acid or nucleotide similarity is evident between this gene and the periplasmic hydrogenases from three species of Desuljovibrio (D. vulgaris, D. baculatus and D. gigas), or with the membrane-bound 'uptake' hydrogenases of Bradyrhizobium japonicum and Rhodobacter capsulatus. This suggests that the soluble enzyme from cyanobacteria represents a discrete class of hydrogenase.The gene encoding the second subunit (m = 50 kDa) of the soluble hydrogenase, which is required for the catalysis of hydrogen production from dithionite-reduced methyl viologen [Ewart, G. D.

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Section: Discussionmentioning

confidence: 99%

Soluble hydrogenase of Anabaena cylindrica

Ewart

Reed

Smith

1990

European Journal of Biochemistry

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“…This last sequence is conserved in all large subunits and may well play a role in metal binding. The data regarding the content of Fe, Ni, and Se in B. japonicum hydrogenase are incomplete (1).…”

Section: Methodsmentioning

confidence: 99%

“…At least 25% of the available electron flux is utilized in H2 production, thus diminishing the potential for N2 fixation (1). However, some strains of rhizobia possess an active H2-uptake (Hup) system that catalyzes H2 oxidation, which results in increased ATP production and decreased levels of dissolved 02 thus providing benefits for the nitrogenase system (1).…”

mentioning

confidence: 99%

Nucleotide sequence of the genetic loci encoding subunits of Bradyrhizobium japonicum uptake hydrogenase.

Sayavedra-Soto

Powell

Evans

et al. 1988

Proc. Natl. Acad. Sci. U.S.A.

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104

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An indispensable part of the hydrogenrecycling system in Bradyrhizobium japonicum is the uptake hydrogenase, which is composed of34.5-and 65.9-kDa subunits. The gene encoding the large subunit is located on a 5.9-kilobase fragment of the H2-uptake-complementing cosmid pHU52 [Zuber, M., Harker, A. R., Sultana, M. A. & Evans, H. J. (1986) Proc. NatI. Acad. Sci. USA 83,[7668][7669][7670][7671][7672]. We have now determined that the structural genes for both subunits are present on this fragment. Two open reading frames are present that correspond in size and deduced amino acid sequence to the hydrogenase subunits, except that the small-subunit coding region contains a leader peptide of46 amino acids. The two genes are separated by a 32-nucleotide intergenic region and likely constitute an operon. Comparison of the deduced amino acid sequences of the B. japonicum genes with those from Desulfovibriogigas, Desulfovibrio baculatus, and Rhodobactercapsultus indicates significant sequence identity.The H2 evolution that accompanies biological N2 fixation represents a large energy expenditure. At least 25% of the available electron flux is utilized in H2 production, thus diminishing the potential for N2 fixation (1). However, some strains of rhizobia possess an active H2-uptake (Hup) system that catalyzes H2 oxidation, which results in increased ATP production and decreased levels of dissolved 02 thus providing benefits for the nitrogenase system (1).Lambert et al. (2) isolated a cosmid, pHU52, from an EcoRI library of Bradyrhizobium japonicum DNA prepared in pLAFR1 (3). It encoded all determinants for H2 recycling in B. japonicum and conferred Hup activity and autotrophic growth capability to Hup-strains of rhizobia. Zuber et al. (4) cloned a 5.9-kilobase (kb) HindIII fragment of pHU52 in a plasmid, pMZ550, and determined by immunological methods that the gene encoding the large subunit of the hydrogenase was located on this fragment. The gene for the small subunit originally was thought to reside on a separate 2.9-kb fragment of pHU52 but was found subsequently to be present on the same 5.9-kb insert in pMZ550 (4).We now report the nucleotide sequence of the relevant region of this insert.$ It encodes structural genes for both the large and small subunits of the B. japonicum hydrogenase. The deduced amino acid sequence of this hydrogenase from B. japonicum is compared to the sequences of hydrogenases from Rhodobacter capsulatus (5), Desulfovibrio gigas (6), Desulfovibrio baculatus (7), and Desulfovibrio vulgaris (8). MATERIALS AND METHODSBacterial Strains. B. japonicum 122DES (9) Transcript Mapping. Total RNA was isolated from 3 g of 30-day-old soybean nodule bacteroids or 0.5 g of autotrophically grown B. japonicum cells (18). Two probes were employed: the first extended from the Mlu I sit! (nucleotide position 69; Fig. 2

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“…Bacteria forming nodules on legume roots may synthetise uptake hydrogenase which recycles the Hz evolved by nitrogenase in the nodules (Evans et al, 1987;Maier, 1986), and contribute to the overall efficiency of the N2 fixation process (Evans et al, 1988). These bacteria include R. leguminosarum bv.…”

Section: Symbiotic Effectiveness and Physiological Assaysmentioning

confidence: 99%

Characterization of rhizobia nodulating Lotus subbiflorus from Uruguayan soils

Irisarri¹,

Milnitsky²,

Monza³

et al. 1996

Plant Soil

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Generation times, acid production, carbon utilization, immunological properties, plasmid content, protein profile and symbiotic properties of 15 isolates of rhizobia nodulating Lotus subbiflorus were studied. Based on specific growth rates, carbon source utilization and acid production, 13 out of the 15 isolates could be assigned to the slow-growing group of rhizobia (bradyrhizobia). Using antisera against whole cells of three isolates, we separated the 15 isolates into three serogroups. Only the slow-growing isolate Ls4 and the fast-growers Ls5 and Ls552 lacked cross-reactivity with any of the sera tested. Electrophoretic mobilities of whole cell protein from seven out of the eight isolates included in the serogroup represented by strain Ls31 were identical. Similarly, isolates Ls 1 B3 and Ls 1B4, both in serogroup Ls 1B3, had the same pattern of cell proteins. In contrast, isolates Ls3 and Ls7, belonging to serogroup Ls7, differed in protein profile. Plant growth experiments carried out under bacteriologically controlled conditions revealed that all of the isolates effectively nodulated L. subbiflorus and L. pedunculatus, but were unable to form effective nodules on L. tenuis and L. corniculatus. All isolates showed similar effectiveness in symbiosis with L. subbiflorus, except isolate Ls7, which gave significantly higher plant dry weight.Abbreviations: ELISA -enzyme linked immuno-sorbent assay, kDa -kiloDalton, MM -mineral medium, PBS -phosphate-buffered saline, RE -relative efficiency, SDS-PAGE -sodium dodecyl sulfate-polyacrylamide gel electrophoresis, YEM -yeast extract mannitol.

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Physiology, Biochemistry, and Genetics of the Uptake Hydrogenase in Rhizobia

Cited by 119 publications

References 45 publications

Soluble hydrogenase of Anabaena cylindrica

Soluble hydrogenase of Anabaena cylindrica

Nucleotide sequence of the genetic loci encoding subunits of Bradyrhizobium japonicum uptake hydrogenase.

Characterization of rhizobia nodulating Lotus subbiflorus from Uruguayan soils

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