| inhibition of hydrogenase synthesis by dna gyrase inhibitors in bradyrhizobium japonicum. | derepression of an uptake hydrogenase in bradyrhizobium japonicum is dependent on a microaerophilic environment. addition of dna gyrase inhibitors during depression of hydrogenase specifically prevented expression of the hydrogenase enzyme. antibodies to individual hydrogenase subunits failed to detect the protein after derepression in the presence of inhibitors, although there was no general inhibition of protein synthesis. the general pattern of proteins synthesized from 14c-labeled amino acid ... | 1987 | 3034865 |
| nitrate reductase from bacteroides of rhizobium japonicum: enzyme characteristics and possible interaction with nitrogen fixation. | the soluble nitrate reductase of rhizobium japonicum bacteroids has been purified and its properties compared to those of aerobically grown cells. the enzymes from both sources are similar with molecular weights of about 70 000 suggesting no close relationship with the molybdo-protein component of nitrogenase. nitrite, the product of nitrate reductase, strongly inhibited the nitrogenase activity from bacteroids, at concentrations less than 100 mum. thus, an interference in the rate of nitrogen f ... | 1975 | 1170894 |
| transposon-induced symbiotic mutants of bradyrhizobium japonicum: isolation of two gene regions essential for nodulation. | two strains of the soybean endosymbiont bradyrhizobium japonicum, usda 110 and 61 a101 c, were mutagenized with transposon tn5. after plant infection tests of a total of 6,926 kanamycin and streptomycin resistant transconjugants, 25 mutants were identified that are defective in nodule formation (nod-) or nitrogen fixation (fix-). seven nod- mutants were isolated from strain usda110 and from strain 61 a101 c, 4 nod- mutants and 14 fix- mutants were identified. subsequent auxotrophic tests on thes ... | 1987 | 3037278 |
| ineffective and non-nodulating mutant strains of rhizobium japonicum. | mutant strains of rhizobium japonicum that were unable to allow the corsoy cultivar of soybean to reduce acetylene or fix n2 were isolated. these strains grow as well as the wild type in a variety of media. mutant strains sm1 and sm2 did not form nodules on the host plant; however, they reduced acetylene in the nonsymbiotic assay. strains sm3 and sm4 produced nodules that did not have the characteristic pink pigment caused by leghemoglobin. the nodules formed by these strains also were small. on ... | 1976 | 986388 |
| nucleotide sequence of the genetic loci encoding subunits of bradyrhizobium japonicum uptake hydrogenase. | an indispensable part of the hydrogen-recycling system in bradyrhizobium japonicum is the uptake hydrogenase, which is composed of 34.5- 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. natl. acad. sci. usa 83, 7668-7672]. we have now determined that the structural genes for both subunits are present on this fragment. two open reading fram ... | 1988 | 3054886 |
| selenium increases hydrogenase expression in autotrophically cultured bradyrhizobium japonicum and is a constituent of the purified enzyme. | we have investigated the effect of added selenite on autotrophic growth and the time course of hydrogen oxidation derepression in bradyrhizobium japonicum 122des cultured in a medium purified to remove selenium compounds. in addition, hydrogenase was purified to near homogeneity and examined for the specific incorporation of se into the enzyme. the addition of se at 0.1 microm significantly increased total cell protein and hydrogenase specific activity of harvested cells. also, the addition of s ... | 1988 | 3056905 |
| cloning and sequencing of the genes encoding the large and the small subunits of the h2 uptake hydrogenase (hup) of rhodobacter capsulatus. | the structural genes (hup) of the h2 uptake hydrogenase of rhodobacter capsulatus were isolated from a cosmid gene library of r. capsulatus dna by hybridization of bradyrhizobium japonicum. the r. capsulatus genes were localized on a 3.5 kb hindiii fragment. the fragment, cloned onto plasmid pac76, restored hydrogenase activity and autotrophic growth of the r. capsulatus mutant jp91, deficient in hydrogenase activity (hup-). the nucleotide sequence, determined by the dideoxy chain termination me ... | 1988 | 3067084 |
| bacteriocin-like substances produced by rhizobium japonicum and other slow-growing rhizobia. | bacteriocin-like substances were commonly produced by slow-growing rhizobium japonicum and cowpea rhizobia on an l-arabinose medium. antagonism between strains of r. japonicum was not detected in vitro; however, such strains were often sensitive to some bacteriocins produced by cowpea rhizobia. inhibitory zones (2 to 8 mm from colony margins), produced by 58 of 66 r. japonicum test strains, were reproducibly detected with corynebacterium nebraskense as an indicator. quantitative production was n ... | 1978 | 570016 |
| activation of the bradyrhizobium japonicum nifh and nifdk operons is dependent on promoter-upstream dna sequences. | previous analysis of b. japonicum nifh'- and nifd'-'lacz translational fusions showed that these promoters could be activated by the k. pneumoniae nifa plus the e. coli ntra gene products. to study the functions of the dna 5' to these promoters, plasmids carrying deletions in this region were constructed and analyzed in vivo in a heterologous system consisting of an e. coli (ntra+) background with a plasmid that constitutively expresses the k. pneumoniae nifa gene. activation of the b. japonicum ... | 1986 | 3086837 |
| expression of uptake hydrogenase and hydrogen oxidation during heterotrophic growth of bradyrhizobium japonicum. | strains i-110 ars, sr, usda 136, usda 137, and ak13 1c of bradyrhizobium japonicum induced hup activity when growing heterotrophically in medium with carbon substrate and nh4cl in the presence of 2% h2 and 2% o2. hup activity was induced during heterotrophic growth in the presence of carbon substrates, which were assimilated during the time of h2 oxidation. strains i-110 ars and sr grown heterotrophically or chemoautotrophically for 3 days had similar rates of h2 oxidation. similar rates of hup ... | 1987 | 3115959 |
| analysis of lectin binding by bradyrhizobium japonicum strains grown on nitrocellulose filters using peroxidase-labeled lectin. | a procedure was developed to assess the ability of wild-type and mutant strains of bradyrhizobium japonicum to bind soybean lectin. the lectin-binding ability of bacteria grown on nitrocellulose filters was determined using peroxidase-labeled soybean lectin. the assay produced clear differences between strains known to be unable to bind soybean lectin and those which can. the assay gave results identical to those of the fluorescein isothiocyanate-soybean lectin-binding assay of t. v. bhuvaneswar ... | 1987 | 3118739 |
| characterization of the rhizobium leguminosarum genes nodlmn involved in efficient host-specific nodulation. | three nodulation genes, nodl, nodm and nodn, were isolated from rhizobium leguminosarum and their dna sequences were determined. the three genes are in the same orientation as the previously described nodfe genes and the predicted molecular weights of their products are 20,105 (nodl), 65,795 (nodm) and 18,031 (nodn). analysis of gene regulation using operon fusions showed that nodl, nodm and nodn are induced in response to flavanone molecules and that this induction is nodd-dependent. in additio ... | 1988 | 3132583 |
| genetically marked rhizobium identifiable as inoculum strain in nodules of soybean plants grown in fields populated with rhizobium japonicum. | the fate of an inoculum strain of rhizobium japonicum was studied using a genetically marked strain i-11o subline carrying resistance markers for azide, rifampin, and streptomycin (i-110 ars). at the time of planting into a field populated with r. japonicum, seeds of soybean cultivars kent and peking were inoculated with varying cell densities of strain i-110 ars. at various times during the growing season, surface-sterilized root nodules were examined for the presence of the inoculum strain by ... | 1978 | 570015 |
| comparison of colony morphology, salt tolerance, and effectiveness in rhizobium japonicum. | four strains of rhizobium japonicum, two of which produce slimy and non-slimy colony types and two others which produce large and small colony types, were isolated and cloned. all were infective and nodulated lee soybean host plants. each colony type was characterized as to its salt sensitivity to na+ and k+ ions, relative level of symbiotic nitrogen fixation, and relative level of free-living nitrogen fixation. growth studies performed in the presence of salts demonstrated that the non-slimy or ... | 1977 | 561643 |
| molybdate transport by bradyrhizobium japonicum bacteroids. | bacteroid suspensions of bradyrhizobium japonicum usda 136 isolated from soybeans grown in mo-deficient conditions were able to transport molybdate at a nearly constant rate for up to 1 min. the apparent km for molybdate was 0.1 microm, and the vmax was about 5 pmol/min per mg (dry weight) of bacteroid. supplementation of bacteroid suspensions with oxidizable carbon sources did not markedly increase molybdate uptake rates. anaerobically isolated bacteroids accumulated twice as much mo in 1 h as ... | 1988 | 3192511 |
| in vitro and in vivo antibacterial activities of me1207, a new oral cephalosporin. | me1207 (pivaloyloxymethyl ester of me1206) is a new oral cephalosporin. me1206 is (6r,7r)-7-[(z)-2-(2-aminothiazol-4-yl)-2-(methoxyimino)- acetamido]-3-[(z)-2-(4-methylthiazol-5-yl)-ethyl]-cephem-4-carboxy lic acid. the susceptibilities of about 1,600 clinical isolates to me1206 were determined by the agar dilution method. me1206 showed a broad spectrum of activity against gram-positive and gram-negative bacteria. me1206 was more active than cefaclor, t-2525, and cefixime against staphylococcus ... | 1988 | 3264132 |
| the symbiotic nitrogen fixation regulatory operon (fixrnifa) of bradyrhizobium japonicum is expressed aerobically and is subject to a novel, nifa-independent type of activation. | the bradyrhizobium japonicum n2 fixation regulatory gene, nifa, was sequenced and its transcription start site determined. between the start of transcription and the nifa gene an open reading frame of 278 codons was found and named fixr. a deletion in fixr which allowed transcription into nifa resulted in a 50% reduced fix activity. the fixrnifa operon was expressed in soybean root nodules, in cultures grown anaerobically with nitrate as terminal electron acceptor, in microaerobic cultures, and ... | 1987 | 3313281 |
| effect of ph on tritium exchange and hydrogen production and uptake in free-living cells and in bacteroids of bradyrhizobium japonicum. | soybean nodule bacteroids and bradyrhizobium japonicum free-living cells induced for h2-uptake hydrogenase, actively catalyze the evolution of h2 in a reaction highly dependent on the ph. the optimal phs for the evolution and uptake reactions were 4.0 and 7.5-8.0, respectively. no differences were found between free-living cells and bacteroids with respect to hydrogen acceptor specificity, although absolute rates of h2 uptake were higher for free-living cells. both types of cells were able to ev ... | 1987 | 3322198 |
| regulation of the fixa gene and fixbc operon in bradyrhizobium japonicum. | the transcriptional start site of the bradyrhizobium japonicum fixbc operon was identified by nuclease s1 mapping. it was located approximately 700 base pairs upstream of fixb and was preceded by a promoter sequence that showed strong homology to the b. japonicum fixa promoter and thus to the general nif consensus promoter sequence. further transcript mapping experiments revealed that fixa and fixbc transcription in b. japonicum strictly depended on the presence of the regulatory gene nifa and o ... | 1988 | 3343218 |
| lack of carbon substrate repression of uptake hydrogenase activity in bradyrhizobium japonicum sr. | the expression of ex planta uptake hydrogenase (hup) activity in bradyrhizobium japonicum sr induced in the absence or presence of carbon substrates was compared. hup activity was influenced by ph, indicating that acidification of induction medium with low buffering capacity resulting from carbon substrate metabolism inhibited hup activity. cell suspensions in medium with adequate buffering capacity and carbon substrate were limited in o2; increasing o2 availability to cells during induction sti ... | 1988 | 3350794 |
| identification of a new bradyrhizobium japonicum gene (frxa) encoding a ferredoxinlike protein. | an open reading frame of 74 codons was identified downstream of the nifb gene of bradyrhizobium japonicum 110. the predicted amino acid sequence shared 63% similarity with the rhodopseudomonas palustris ferredoxin i sequence. we propose to name the gene frxa. the frxa gene was found to be cotranscribed with the nifb gene. an insertion mutation within frxa hardly affected nitrogen fixation activity. | 1988 | 3350797 |
| essential and non-essential domains in the bradyrhizobium japonicum nifa protein: identification of indispensable cysteine residues potentially involved in redox reactivity and/or metal binding. | the amino acid sequence of the bradyrhizobium japonicum nitrogen fixation regulatory protein nifa, as derived from the nucleotide sequence of the nifa gene, was aligned to the corresponding protein sequences from klebsiella pneumoniae, rhizobium meliloti and rhizobium leguminosarum biovar viciae. high conservation was found in the central domain and in the cooh-terminal, putative dna binding domain, whereas very little homology was present within the first 250 amino acids from the nh2-terminus. ... | 1988 | 3357773 |
| quantitative assay for binding of bradyrhizobium japonicum to cultured soybean cells. | incubation of bradyrhizobium japonicum with the cultured soybean cell line sb-1 resulted in the adhesion of the bacteria to the plant cells. an antiserum was raised against b. japonicum, and the 125i-labeled immunoglobulin fraction was used to quantitate the number of bacteria bound to the soybean cells. the measurement of 125i-labeled antibody binding correlated well with parallel assays by microscopic observation. using this quantitation, we have optimized the parameters of the assay in terms ... | 1988 | 3410819 |
| dicarboxylic acid transport in bradyrhizobium japonicum: use of rhizobium meliloti dct gene(s) to enhance nitrogen fixation. | a recombinant plasmid encoding rhizobium meliloti sequences involved in dicarboxylic acid transport (plasmid prk290:4:46) (e. bolton, b. higgisson, a. harrington, and f. o'gara, arch. microbiol. 144:142-146, 1986) was used to study the relationship between dicarboxylic acid transport and nitrogen fixation in bradyrhizobium japonicum. the expression of the dct sequences on plasmid prk290:4:46 in b. japonicum cj1 resulted in increased growth rates in media containing dicarboxylic acids as the sole ... | 1988 | 3422072 |
| laboratory and clinical evaluation of isolation media for campylobacter jejuni. | six selective isolation media were evaluated for their ability to support the growth of campylobacter jejuni. colony counts of 70 isolated strains of c. jejuni and recovery studies on these strains in simulated positive feces samples demonstrated that bolton and hutchinson' charcoal, cefoperazone, deoxycholate agar and karmali's charcoal-based selective medium produced the highest recovery rates with the greatest suppression of other fecal flora. c. jejuni colonies were more easily recognized on ... | 1987 | 3429621 |
| organization and characterization of genes essential for symbiotic nitrogen fixation from bradyrhizobium japonicum i110. | a total of 96 independent tn5 insertions within a 39-kilobase-pair (kbp) segment of chromosomal dna containing the three structural genes for nitrogenase (nifh, nifd, and nifk) from bradyhizobium japonicum i110 were obtained in escherichia coli and transferred to the wild-type strain by marker exchange. individual transconjugants containing a tn5 insertion were inoculated onto glycine max cv. wilkin (soybeans) and analyzed for their effect on symbiotic nitrogen fixation. in addition to the three ... | 1986 | 3462181 |
| nitrogenase promoter-lacz fusion studies of essential nitrogen fixation genes in bradyrhizobium japonicum i110. | dna fragments containing either the nifd or nifh promoter and 5' structural gene sequences from bradyrhizobium japonicum i110 were fused in frame to the lacz gene. stable integration of these nif promoter-lacz fusions by homologous double reciprocal crossover into a symbiotically nonessential region of the b. japonicum chromosome provided an easy assay for the effects of potential nif regulatory mutants. the level of beta-galactosidase activity expressed from these two nif promoter-lacz fusions ... | 1986 | 3462182 |
| [lysogeny of rhizobium japonicum and the sensitivity of these cultures to phages isolated from soil]. | twenty cultures of rhizobium japonicum of various origin were tested for lysogeny using a cross technique with a preliminary uv induction and without it as well as by electron microscopy. none of the cultures was found in the lysogenic state. phages active against rh. japonicum were detected in four soil samples on which soybean plants were grown; 27 phages were isolated by the enrichment method and 3 phages without enrichment. the phages were capable of lysis of only rh. japonicum cultures and ... | 1979 | 440166 |
| regulation of hydrogenase in rhizobium japonicum. | factors that regulate the expression of an h2 uptake system in free-living cultures of rhizobium japonicum have been investigated. rapid rates of h2 uptake by r. japonicum were obtained by incubation of cell suspensions in a mg-phosphate buffer under a gas phase of 86.7% n2, 8.3% h2, 4.2% co2, and 0.8% o2. cultures incubated under conditions comparable with those above, with the exception that ar replaced h2, showed no hydrogenase activity. when h2 was removed after initiation of hydrogenase der ... | 1979 | 422513 |
| iron-sulfur clusters in the molybdenum-iron protein component of nitrogenase. electron paramagnetic resonance of the carbon monoxide inhibited state. | carbon monoxide inhibits reduction of dinitrogen (n2) by purified nitrogenase from azotobacter vinelandii and clostridium pasteurianum in a noncompetitive manner (kii and kis = 1.4 x 10(-4) and 4.5 x 10(-4) and 7 x 10(-4) atm and 14 x 10(-4) atm for the two enzymes, respectively). the onset of inhibition is within the turnover time of the enzyme, and co does not affect the electron flux to the h2-evolving site. the kinetics of co inhibition of n2 reduction are simple, but co inhibition of acetyl ... | 1979 | 228701 |
| immunological homology between the membrane-bound uptake hydrogenases of rhizobium japonicum and escherichia coli. | two polypeptides present in aerobic and anaerobic cultures of escherichia coli hb101 were shown to cross-react with antibodies to the 30- and 60-kilodalton (kda) subunits of the uptake hydrogenase of rhizobium japonicum. the cross-reactive polypeptides in a series of different e. coli strains are of mrs ca. 60,000 and 30,000, and both polypeptides are present in proportion to measurable hydrogen uptake (hup) activity (r = 0.95). the 60-kda polypeptide from e. coli hb101 comigrated on native gels ... | 1986 | 3511036 |
| expression and regulation of the escherichia coli glutamate dehydrogenase gene (gdh) in rhizobium japonicum. | the glutamate dehydrogenase (gdh) gene of escherichia coli was transferred into an ammonium assimilation deficient mutant (asm-) of rhizobium japonicum (cj9) using plasmid prp301, a broad host range derivative of rp4. exconjugants capable of growth on ammonia as sole n-source occurred at a frequency of 6.8 x 10(-6). assimilatory gdh (nadp+) activity was detected in the strain carrying the e. coli gdh gene and the pattern of ammonia assimilation via gdh was similar to that of the asm+ wild type s ... | 1986 | 3516109 |
| aerobic purification of hydrogenase from rhizobium japonicum by affinity chromatography. | we purified active hydrogenase from free-living rhizobium japonicum by affinity chromatography. the uptake hydrogenase of r. japonicum has been treated previously as an oxygen-sensitive protein. in this purification, however, reducing agents were not added nor was there any attempt to exclude oxygen. in fact, the addition of sodium dithionite to aerobically purified protein resulted in the rapid loss of activity. purified hydrogenase was more stable when stored under o2 than when stored under ar ... | 1986 | 3519580 |
| reversible inactivation of the o2-labile hydrogenases from azotobacter vinelandii and rhizobium japonicum. | hydrogenases catalyze the reversible activation of dihydrogen. the hydrogenases from the aerobic, n2-fixing microorganisms azotobacter vinelandii and rhizobium japonicum are nickel- and iron-containing dimers that belong to the group of o2-labile enzymes. exposure of these hydrogenases to o2 results in an irreversible inactivation; therefore, these enzymes are purified anaerobically in a fully active state. we describe in this paper an electron acceptor-requiring and ph-dependent, reversible ina ... | 1986 | 3525552 |
| effect of lindane on radio-carbon (14c) incorporation by rhizobium japonicum. | experiments conducted in vitro with three levels (1, 2, and 5 ppm active ingredient) of the insecticide lindane (gamma-bhc) showed no effect on the growth of rhizobium japonicum, but altered the incorporation of radio-carbon (14c-glucose) into the different constituents of the growing cells. while all the three levels of the insecticide significantly depressed the incorporation of radiocarbon in the alcohol-extractable fraction, with no effect on the alcohol-ether soluble fraction of the cells, ... | 1976 | 65064 |
| cloning and expression of bradyrhizobium japonicum uptake hydrogenase structural genes in escherichia coli. | to identify the structural genes for the components of bradyrhizobium japonicum uptake hydrogenase (mr 60,000 and 30,000), we have expressed these genes in escherichia coli and shown that the products cross-react with antibodies to the respective hydrogenase subunits. we constructed subclones of overlapping dna fragments from an uptake hydrogenase-complementing cosmid, phu52 [lambert, g. r., cantrell, m. a., hanus, f. j., russell, s. a., haddad, k. r. & evans, h. j. (1985) proc. natl. acad. sci. ... | 1986 | 3532119 |
| nucleotide sequence of the gene encoding the nitrogenase iron protein of thiobacillus ferrooxidans. | the dna sequence was determined for the cloned thiobacillus ferrooxidans nifh and part of the nifd genes. a putative t. ferrooxidans nifh promoter was identified whose sequences showed perfect consensus with those of the klebsiella pneumoniae nif promoter. two putative consensus upstream activator sequences were also identified. the amino acid sequence was deduced from the dna sequence. in a comparison of nifh dna sequences from t. ferrooxidans and eight other nitrogen-fixing microbes, a rhizobi ... | 1987 | 3539923 |
| regulation of nitrogen fixation by rhizobia. export of fixed n2 as nh+4. | the metabolic fate of gaseous nitrogen (15n2) fixed by free-living cultures of rhizobia (root nodule bacteria) induced for their n2-fixation system was followed. a majority of the fixed 15n2 was found to be exported into the cell supernatant. for example, as much as 94% of the 15n2 fixed by rhizobium japonicum (soybean symbiont) was recovered as 15nh+4 from the cell supernatant following alkaline diffusion. several species of root nodule bacteria also exported large quantities of nh+4 from l-his ... | 1976 | 8100 |
| a locus encoding host range is linked to the common nodulation genes of bradyrhizobium japonicum. | by using cloned rhizobium meliloti, rhizobium leguminosarum, and rhizobium sp. strain mpik3030 nodulation (nod) genes as hybridization probes, homologous regions were detected in the slow-growing soybean symbiont bradyrhizobium japonicum usda 110. these regions were found to cluster within a 25-kilobase (kb) region. specific nod probes from r. meliloti were used to identify noda-, nodb-, nodc-, and nodd-like sequences clustered on two adjacent hindiii restriction fragments of 3.9 and 5.6 kb. a 7 ... | 1987 | 3584066 |
| structure of the bradyrhizobium japonicum gene hema encoding 5-aminolevulinic acid synthase. | the nucleotide (nt) sequence of the hema gene, which encodes 5-aminolevulinic acid synthase (alas) from the bacterium bradyrhizobium japonicum, is presented. this sequence predicts a protein of 408 amino acids (aa) with an mr of 44,599. this predicted amino acid sequence is highly homologous to that of the chicken embryonic liver alas, exhibiting a 48.8% identical amino acid sequence over the entire length of the bacterial protein. a single mrna start point was demonstrated by s1 protection anal ... | 1987 | 3609750 |
| mapping and nucleotide sequence of the nifs promoter of bradyrhizobium japonicum. | | 1987 | 3684606 |
| fructose 1,6-bisphosphate aldolase activity of rhizobium species. | fdp aldolase was found to be present in the cell-free extracts of rhizobium leguminosarum, rhizobium phaseoli, rhizobium trifolii, rhizobium meliloti, rhizobium lupini, rhizobium japonicum and rhizobium species from arachis hypogaea and sesbania cannabina. the enzyme in 3 representative species has optimal activity at ph 8.4 in 0.2m veronal buffer. the enzyme activity was completely lost by treatment at 60 degrees c for 15 min. the km values were in the range from 2.38 to 4.55 x 10(-6)m fdp. met ... | 1975 | 283 |
| cell surface polysaccharides from bradyrhizobium japonicum and a nonnodulating mutant. | the cell surface polysaccharides of wild-type bradyrhizobium japonicum usda 110 and a nonnodulating mutant, strain hs123, were analyzed. the capsular polysaccharide (cps) and exopolysaccharide (eps) of the wild type and the mutant strain do not differ in their sugar composition. cps and eps are composed of mannose, 4-o-methylgalactose/galactose, glucose, and galacturonic acid in a ratio of 1:1:2:1, respectively. h nuclear magnetic resonance spectra of the eps and cps of the wild type and mutant ... | 1987 | 3793715 |
| nodulin-26, a peribacteroid membrane nodulin is expressed independently of the development of the peribacteroid compartment. | the peribacteroid membrane (pbm) of root nodules is derived from the plant cell plasma membrane but contains in addition several nodule-specific host proteins (nodulins). antibodies raised against purified pbm of soybean were used to immunoprecipitate polysomes to isolate an rna fraction that served as a template for the synthesis of a cdna probe for screening a nodule-specific cdna library. clone p1b1 was found to encode a 26.5 kda polypeptide (nodulin-26) which is immunoprecipitable specifical ... | 1987 | 3822816 |
| isolation of genes (nif/hup cosmids) involved in hydrogenase and nitrogenase activities in rhizobium japonicum. | recombinant cosmids containing a rhizobium japonicum gene involved in both hydrogenase (hup) and nitrogenase (nif) activities were isolated. an r. japonicum gene bank utilizing broad-host-range cosmid plafr1 was conjugated into hup- nif- r. japonicum strain sr139. transconjugants containing the nif/hup cosmid were identified by their resistance to tetracycline (tcr) and ability to grow chemoautotrophically (aut+) with hydrogen. all tcr aut+ transconjugants possessed high levels of h2 uptake acti ... | 1985 | 3882669 |
| further evidence that two unique subunits are essential for expression of hydrogenase activity in rhizobium japonicum. | eight strains of rhizobium lacking hydrogenase uptake (hup) activity and 17 transconjugant strains carrying the hup cosmids phu1, phu52, or phu53 (g. r. lambert, m. a. cantrell, f. j. hanus, s. a. russell, k. r. haddad, and h. j. evans, proc. natl. acad. sci. usa, 82:3232-3236, 1985) were screened for hup activity and the presence of immunologically detectable hydrogenase polypeptides. crude extracts of these strains were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ... | 1985 | 3900036 |
| rhizobium japonicum hydrogenase: purification to homogeneity from soybean nodules, and molecular characterization. | rhizobium japonicum hydrogenase was purified to homogeneity from soybean root nodules by four column chromatography steps after solubilization from membranes by treatment with a nonionic detergent. the specific activity was from 40 to 65 mumol h2 oxidized min-1 mg protein-1 and was increased 450-fold relative to that in bacteroids. the yield of activity was from 7 to 12%. the molecular weight of the native enzyme was 104,000 as determined by sucrose density gradient centrifugation. electrophores ... | 1985 | 3919648 |
| nitric oxide-dependent proton translocation in various denitrifiers. | respiration of no resulted in transient proton translocation in anaerobically grown cells of four physiologically diverse denitrifiers. paracoccus denitrificans, rhodopseudomonas sphaeroides subsp. denitrificans, "achromobacter cycloclastes," and rhizobium japonicum gave, respectively, h+/no ratios of 3.65, 4.96, 1.94, and 1.12. antimycin a completely inhibited no-dependent proton translocation in p. denitrificans and severely restricted translocation in the r. sphaeroides strain. proton uptake ... | 1985 | 3928599 |
| characterization of hydrogen-uptake activity in the hyperthermophile pyrodictium brockii. | pyrodictium brockii is a hyperthermophilic archaebacterium with an optimal growth temperature of 105 degrees c. p. brockii is also a chemolithotroph, requiring h2 and co2 for growth. we have characterized p. brockii hydrogen-uptake activity with regard to temperature, ability to couple hydrogen oxidation to artificial electron acceptor reduction, sensitivity to o2, and cellular localization. the hydrogen-uptake activity was localized predominantly in a particulate fraction, was reversibly inhibi ... | 1989 | 2492097 |
| enzymes of the beta-ketoadipate pathway are inducible in rhizobium and agrobacterium spp. and constitutive in bradyrhizobium spp. | protocatechuate is a universal growth substrate for members of the family rhizobiaceae, and these bacteria utilize the aromatic compound via the beta-ketoadipate pathway. this report describes transcriptional controls exercised by different subgroups of the rhizobiaceae over five enzymes that catalyze consecutive reactions in the pathway: protocatechuate oxygenase (ec 1.13.11.3), beta-carboxy-cis,cis-muconate lactonizing enzyme (ec 5.5.1.2), gamma-carboxymuconolactone decarboxylase (ec 4.1.1.44) ... | 1986 | 3941043 |
| o-antigen from bradyrhizobium japonicum lipopolysaccharide inhibits intercellular (symplast) communication between soybean (glycine max) cells. | the technique of fluorescence redistribution after photobleaching was utilized to measure intercellular movement of low molecular weight fluorescent hydrophilic substances across the cell wall/membrane interface between contiguous soybean (glycine max (l.) merr. cv. mandarin) root cells (sb-1 cell line) in tissue culture. lipopolysaccharide (lps) purified from bradyrhizobium japonicum r110d, a gram-negative bacterium that normally infects and induces nodulation in soybean roots in vivo, inhibits ... | 1989 | 2473070 |
| expression of cytochrome o in hydrogen uptake constitutive mutants of rhizobium japonicum. | mutant strains of rhizobium japonicum constitutive for h2 uptake activity (hupc) contained significantly more membrane-bound b-type cytochrome than did the wild type when grown heterotrophically. the hupc strains contained approximately three times more dithionite- and nadh-reducible co-reactive b-type cytochrome than did the wild type; the absorption features of the co spectra were characteristic of cytochrome o. this component, designated cytochrome b', was not reduced by nadh in the presence ... | 1985 | 3968033 |
| role of ubiquinone in hydrogen-dependent electron transport in rhizobium japonicum. | direct evidence for the involvement of ubiquinone in h2 oxidation by rhizobium japonicum was demonstrated; h2 reduced ca. 80% of the extractable ubiquinone. the inhibitor 2-n-heptyl-4-hydroxyquinoline-n-oxide blocked electron transport at a site between ubiquinone and the cytochromes. the results showed that no cytochrome component mediates electron flow from hydrogen to ubiquinone. | 1985 | 3968040 |
| molecular and immunological comparison of membrane-bound, h2-oxidizing hydrogenases of bradyrhizobium japonicum, alcaligenes eutrophus, alcaligenes latus, and azotobacter vinelandii. | the membrane-bound hydrogenases of bradyrhizobium japonicum, alcaligenes eutrophus, alcaligenes latus, and azotobacter vinelandii were purified extensively and compared. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of each hydrogenase revealed two prominent protein bands, one near 60 kilodaltons and the other near 30 kilodaltons. the migration distances during nondenaturing polyacrylamide gel electrophoresis were similar for all except a. vinelandii hydrogenase, which migrated furth ... | 1985 | 4008438 |
| conservation of symbiotic nitrogen fixation gene sequences in rhizobium japonicum and bradyrhizobium japonicum. | southern hybridization with nif (nitrogen fixation) and nod (nodulation) dna probes from rhizobium meliloti against intact plasmid dna of rhizobium japonicum and bradyrhizobium japonicum strains indicated that both nif and nod sequences are on plasmid dna in most r. japonicum strains. an exception is found with r. japonicum strain usda194 and all b. japonicum strains where nif and nod sequences are on the chromosome. in r. japonicum strains, with the exception of strain usda205, both nif and nod ... | 1985 | 4008441 |
| cloning and sequencing the genes encoding uptake-hydrogenase subunits of rhodocyclus gelatinosus. | rhodocyclus gelatinosus grew photosynthetically in the light and consumed h2 at a rate of about 665 nmol/min per mg protein. the uptake-hydrogenase (h2ase) was found to be membrane bound and insensitive to inhibition by co. the structural genes of r. gelatinosus uptake-h2ase were isolated from a 40 kb cosmid gene library of r. gelatinosus dna by hybridization with the structural genes of uptake-h2ase of bradyrhizobium japonicum and rhodobacter capsulatus. the r. gelatinosus genes were localized ... | 1990 | 2325631 |
| [the influence of acidic conditions on polar exopolysaccharides which bind rhizobium japonicum to soybean root hairs]. | the influence of acidic conditions on rhizobial exopolysaccharides (eps) and their symbiotic association in host plants, were investigated. light micrographs of soybean root hairs were taken with a fahraeus' slide assembly after the inocubation of rhizobial bacteria; curled and swollen root hairs, and the typical shepherd's crook with an infection thread were observed. the colonizations of soybean root hairs by rhizobia were different under acidic and neutral conditions. for the rhizobium japoni ... | 1985 | 4042755 |
| ammonia regulation of nod genes in bradyrhizobium japonicum. | the expression of the nodd and nodyabc operons of bradyrhizobium japonicum is repressed by the addition of ammonia. repression of nodyabc expression is probably due to the effect on nodd since nodd positively regulates itself, as well as other nod operons. the effect of ammonia is independent of the known nitrogen regulatory protein, ntrc, and another regulatory protein for nitrogen fixation, nifa. | 1990 | 2250656 |
| heterologous hybridization of bacterial dna to the endoglucanases a and b structural genes cela and celb of clostridium thermocellum. | dna from various cellulolytic and non-cellulolytic bacteria was found to hybridize to clostridium thermocellum ncib10682 dna fragments carrying the structural genes cela and celb which code for endoglucanases a and b. homology to cela was detected in agrobacterium rhizogenes, azospirillum brasilense, bacillus subtilis, cellulomonas sp., clostridium stercorarium, erwinia chrysanthemi, pseudomonas solanacearum and streptomyces griseus. homology to celb was detected only in b. subtilis, c. stercora ... | 1985 | 4083831 |
| isolation and partial characterization of the extracellular polysaccharides and lipopolysaccharides from fast-growing rhizobium japonicum usda 205 and its nod- mutant, hc205, which lacks the symbiotic plasmid. | the extracellular polysaccharides and lipopolysaccharides (lpss) from two fast-growing rhizobium japonicum strains, usda 205 and hc205, were isolated and partially characterized. strain hc205 is a nod- mutant of usda 205 which lacks the symbiotic plasmid. the extracellular polysaccharides from both strains are very similar in composition, having galactose, glucose, glucuronic acid, and acyl groups. the extracellular polysaccharides do not contain detectable levels of pyruvate. methylation analys ... | 1985 | 4091554 |
| fluorescent-antibody approach to study of rhizobia in soil. | application of fluorescent-antibody (fa) techniques to the study of rhizobia as free-living soil bacteria was explored. antiserum to a particular strain of rhizobium japonicum proved specific in both agglutination and fa tests. within the r. japonicum group, 2 of 12 strains were stained by the conjugate and these fluoresced brightly; all others were entirely negative. fa tests were negative for 7 strains of r. meliloti, 9 strains of r. leguminosarum, 9 strains of r. trifolii, 6 strains of r. pha ... | 1968 | 4174666 |
| competition between inoculum strains of rhizobium japonicum in the process of soybean nodulation during three planting periods. | | 1973 | 4201820 |
| relationship between soybean cultivars and rhizobium japonicum serotypes with single- and multi-strain inoculants. i. greenhouse pot experiments. | | 1973 | 4205244 |
| the phospholipid composition of rhizobium japonicum. | | 1971 | 4323346 |
| electron paramagnetic resonance and temperature dependent spin state studies of ferric cytochrome p-450 from rhizobium japonicum. | | 1972 | 4339738 |
| anaerobic-nitrate, symbiotic and aerobic growth of rhizobium japonicum: effects on cytochrome p 450 , other haemoproteins, nitrate and nitrite reductases. | | 1972 | 4341774 |
| l-arabinose metabolism in rhizobium japonicum. | l-arabinose was metabolized through an oxidative pathway by extracts of a strain of rhizobium japonicum. the findings showed that l-arabinose is converted into 2-keto-3-deoxy-l-arabonate, which is cleaved into glycoaldehyde and pyruvate. | 1974 | 4407017 |
| streptomycin resistance in rhizobium japonicum. | | 1974 | 4441216 |
| transformation of effectiveness in rhizobium japonicum. | | 1974 | 4477931 |
| transmissible resistance to penicillin g, neomycin, and chloramphenicol in rhizobium japonicum. | the genetic basis for resistance to a number of antibiotics was examined in rhizobium japonicum. resistance to penicillin g, neomycin, and chloramphenicol appears to be mediated by an extrachromosomal element similar to that found in the enterobacteriaceae. resistance to these antibiotics was eliminated from cells by treatment with acridine orange, and resistance to all three antibiotics could be transferred en bloc to agrobacterium tumefaciens under conditions excluding transformation or transd ... | 1973 | 4491197 |
| deoxyribonucleate binding and transformation in rhizobium jpaonicum. | rhizobium japonicum, capable of binding high-molecular-weight donor (32)p-labeled deoxyribonucleic acid (dna) during late log phase in a competence medium, was transformed for streptomycin resistance with a frequency of transformation ranging between 0.02 and 0.08%. eight to 10% of the homologous native (32)p-labeled input dna was bound irreversibly in a temperature-dependent manner. homologous denatured (32)p-labeled dna was incapable of binding to the recipient under similar conditions. cscl d ... | 1972 | 4538250 |
| compatibility of different fungicides with rhizobium japonicum. | | 1972 | 4564552 |
| a simple medium for quick growth of rhizobium japonicum. | | 1973 | 4580100 |
| analysis of the intracellular amino acid pool and proteins from whole cells of rhizobium japonicum. | | 1973 | 4583873 |
| survival of rhizobium japonicum in various carriers. | | 1973 | 4801277 |
| relationship between soybean cultivars and rhizobium japonicum serotypes with single- and multi-strain inoculants. ii. field experiments. | | 1973 | 4801803 |
| distribution of the isopropylmalate pathway to leucine among diverse bacteria. | alpha-isopropylmalate synthase and beta-isopropylmalate dehydrogenase activities were detected in extracts of the following organisms: chromatium d, rhodopseudomonas spheroides, hydrogenomonas h16, pseudomonas aeruginosa, pseudomonas fluorescens, vibrio extorquens, rhizobium japonicum, alcaligenes viscolactis, escherichia coli b, proteus vulgaris, aerobacter aerogenes, salmonella typhimurium, micrococcus sp., micrococcus lysodeikticus, bacillus polymyxa, bacillus subtilis, and nocardia opaca. th ... | 1974 | 4829932 |
| [enzymes intervening in the formation of nucleotide-sugars in rhizobium japonicum]. | | 1967 | 4962178 |
| electron transport systems of rhizobium japonicum. i. haemoprotein p-450, other co-reactive pigments, cytochromes and oxidases in bacteroids from n2-fixing root nodules. | | 1969 | 4974059 |
| electron transport systems of rhizobium japonicum. ii. rhizobium haemoglobin, cytochromes and oxidases in free-living (cultured) cells. | | 1969 | 4974060 |
| serological analysis of eleven strains of rhizobium japonicum. | | 1969 | 4977516 |
| transformation of infectivity in rhizobium japonicum. | | 1970 | 4994104 |
| antigenic analysis of rhizobium japonicum by immunodiffusion. | immunodiffusion reactions were studied with seven strains of rhizobium japonicum and three strains of the cowpea miscellany by using antisera against eight of the strains. most strains yielded only weak precipitin bands when untreated cell suspensions were used as antigens in the diffusions. ultrasonic disruption or heat treatment of the cells led to stronger bands, and immersion in boiling water for 20 min was used as the standard procedure for preparing these bacteria for immunodiffusion analy ... | 1971 | 4998353 |
| interactions between an unusual aspartate aminotransferase from rhizobium japonicum and pyridoxal-5'-phosphate studied by affinity chromatography. | | 1972 | 5085272 |
| the biosynthesis of aspartic acid, glutamic acid, and alanine in rhizobium japonicum. | | 1971 | 5087891 |
| effect of azotobacter chroococcum and tryptophan on the inoculation of soybean (glycine max (l.) merril) with rhizobium japonicum. | | 1969 | 5271557 |
| transformation in rhizobium japonicum. | | 1969 | 5365772 |
| the regulation of some enzymes involved in ammonia assimilation by rhizobium japonicum. | | 1969 | 5370296 |
| competition between two somatic serotypes of rhizobium japonicum used as double-strain inocula in varying proportions. | | 1969 | 5394016 |
| effect of biotin on fatty acids and phospholipids of biotin-sensitive strains of rhizobium japonicum. | the effect of biotin on fatty acids and intact lipids was studied by comparing a biotin-requiring, a biotin-inhibited, and a biotin-indifferent strain of rhizobium japonicum. these organisms were grown in a defined medium with added levels of 0, 0.3, and 0.5 mug of biotin per liter, and were analyzed for fatty acids and lipid components. myristic, palmitic, and octadecenoic acids were found to be the major fatty acids in these strains. the indifferent strain also contained large amounts of c(19) ... | 1970 | 5437727 |
| citrate as a siderophore in bradyrhizobium japonicum. | under iron-limiting conditions, many bacteria secrete ferric iron-specific ligands, generically termed siderophores, to aid in the sequestering and transport of iron. one strain of the nitrogen-fixing soybean symbiont bradyrhizobium japonicum, 61a152, was shown to produce a siderophore when 20 b. japonicum strains were screened with all six chemical assays commonly used to detect such production. production by strain 61a152 was detected via the chrome azurol s assay, a general test for sideropho ... | 1990 | 2140566 |
| molecular biology studies of the uptake hydrogenase of rhodobacter capsulatus and rhodocyclus gelatinosus. | in the photosynthetic bacteria, as in other n2-fixing bacteria, two main enzymes are involved in h2 metabolism: nitrogenase, which catalyses the photoproduction of h2, and a membrane-bound (nife) hydrogenase, which functions as an h2-uptake enzyme. the structural genes for rhodobacter capsulatus and rhodocyclus gelatinosus uptake hydrogenases were isolated and sequenced. they present the same organization, with the gene encoding the small subunit (hups) (molecular masses 34.2 and 34.6 kda, respe ... | 1990 | 2094292 |
| periplasmic metabolism of glutamate and aspartate by intact bradyrhizobium japonicum bacteroids. | in studies on the uptake and metabolism of [14c]glutamate by bradyrhizobium japonicum bacteroids we found that, in the presence of unlabeled malate, succinate or alpha-ketoglutarate, substantial label was recovered in alpha-ketoglutarate in the reaction mixtures. as much as 30% of the total 14c supplied could be found in alpha-ketoglutarate in the reaction mixtures after 30 min and this occurred in the absence of detectable labeling of alpha-ketoglutarate in the cells. the labeling of alpha-keto ... | 1990 | 1976384 |
| an unusual gene cluster for the cytochrome bc1 complex in bradyrhizobium japonicum and its requirement for effective root nodule symbiosis. | two adjacent genes in bradyrhizobium japonicum, fbcf and fbch, encode the rieske iron sulfur protein and cytochromes b and c1, characteristic constituents of the respiratory complex iii. remarkably, fbch is a single gene of which the 5' half codes for cytochrome b and the 3' half codes for cytochrome c1. experimental evidence suggests that a large fbch precursor is posttranslationally processed into the two proteins. b. japonicum fbcf and fbch insertion mutants grow aerobically but are unable to ... | 1989 | 2541921 |
| hydrogenase synthesis in bradyrhizobium japonicum hupc mutants is altered in sensitivity to dna gyrase inhibitors. | in the hupc mutants of bradyrhizobium japonicum sr, regulation of expression of hydrogenase is altered; the mutants synthesize hydrogenase constitutively in the presence of atmospheric levels of oxygen. the dna gyrase inhibitors nalidixic acid, novobiocin, and coumermycin were used to inhibit growth of wild-type and mutant cells. for each inhibitor tested, growth of mutant and wild-type strains was equally sensitive. however, in contrast to the wild type, the hupc mutants synthesized hydrogenase ... | 1989 | 2547335 |
| mutational analysis of the bradyrhizobium japonicum common nod genes and further nod box-linked genomic dna regions. | by insertional and deletional marker replacement mutagenesis the common nod region of bradyrhizobium japonicum was examined for the presence of additional, essential nodulation genes. an open reading frame located in the 800 bp large intergenic region between nodd1 and noda did not appear to be essential for nodulation of soybean. furthermore, a strain with a deletion of the nodi- and nodj-like genes downstream of nodc had a nod+ phenotype. a mutant with a 1.7 kb deletion immediately downstream ... | 1989 | 2710106 |
| cytoplasmic membrane systems involved in bacterium release into soybean nodule cells as studied with two bradyrhizobium japonicum mutant strains. | two bradyrhizobium japonicum, tn5-induced, mutant strains, ml126 and ml150, were studied. both induce host cell division to form normal-sized nodules that do not fix nitrogen and whose cells have very few bacteroids (bar-). early-infection (15 days post infection) cells have much endoplasmic reticulum (er), numerous golgi bodies, and large vacuoles that are probably secondary lysosomes. later the cytoplasm of the host cells of both are dominated by hundreds of vesicles containing only finely fib ... | 1989 | 2759102 |
| critical spacing between two essential cysteine residues in the interdomain linker of the bradyrhizobium japonicum nifa protein. | a special sequence motif in the bradyrhizobium japonicum nifa protein, consisting of two functionally essential cysteines separated by four other amino acids (cys-aa4-cys), has been proposed to be part of a potential metal-binding site [(1988) nucleic acids res. 16, 2207-2224]. using the techniques of oligonucleotide-directed mutagenesis, we report here that several of the four intervening amino acids can be replaced by others without loss of nifa function. the deletion of one amino acid to give ... | 1989 | 2792368 |
| slow-growing rhizobium japonicum comprises two highly divergent symbiotic types. | we examined the interrelationships of the genomes of 10 slow-growing strains of rhizobium japonicum to provide a foundation for molecular genetic studies of these agriculturally important endosymbiotic bacteria of commercial soybeans. the degree of base substitution in and around known symbiotic genes (nif and presumptive nod), constitutively expressed genes (glna and reca), and two other cloned sequences was estimated from restriction site variation by using cloned dnas as hybridization probes ... | 1985 | 2989244 |
| a genetic locus essential for formate-dependent growth of bradyrhizobium japonicum. | a genetic locus essential for the formate-dependent growth of bradyrhizobium japonicum was isolated by complementation of ethyl methanesulfonate-induced mutants with a cosmid gene library of b. japonicum dna. three related cosmids containing 18.7 kilobase pairs of b. japonicum dna in common were identified as being able to restore formate-dependent growth capability to mutants lacking either ribulosebisphosphate carboxylase or both ribulosebisphosphate carboxylase and phosphoribulokinase activit ... | 1987 | 3036781 |