Hairy vetch (Vicia villosa Roth) is a leguminous crop widely used as green manure and a cover crop in Japan. It exhibits strong weed-suppressing activity, high resistance to insect pests, and the ability to fix nitrogen through symbiotic interactions with soil bacteria known as rhizobia. Few studies have investigated the rhizobia that form nodules on hairy vetch in Japan, and the biological res...

LpxE, a membrane-bound phosphatase found in Rhizobium leguminosarum and some other Gram-negative bacteria, selectively dephosphorylates the 1-position of lipid A on the outer surface of the inner membrane. LpxE belongs to the family of lipid phosphate phosphatases that contain a tripartite active site motif and six predicted transmembrane helices. Here we report the purification and characteriz...

In membranes of Rhizobium leguminosarum bacteroids isolated from nitrogen-fixing pea root nodules, two different protein complexes with NADH dehydrogenase activity were detected. One of these complexes, with a molecular mass of 110 kilodaltons, was also found in membranes of free-living rhizobia, but the other, with a molecular mass of 550 kilodaltons, appeared to be present only in bacteroids....

PTS(Ntr) is a regulatory phosphotransferase system in many bacteria. Mutation of the PTS(Ntr) enzymes causes pleiotropic growth phenotypes, dry colony morphology and a posttranslational inactivation of ABC transporters in Rhizobium leguminosarum 3841. The PTS(Ntr) proteins EI(Ntr) and 2 copies of EIIA(Ntr) have been described previously. Here we identify the intermediate phosphocarrier protein ...

Rhizobium leguminosarum bv. trifolii SRDI943 (strain syn. V2-2) is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from a root nodule of Trifolium michelianum Savi cv. Paradana that had been grown in soil collected from a mixed pasture in Victoria, Australia. This isolate was found to have a broad clover host range but was sub-optimal for nitrogen fixation with T. sub...

Effects of cell density, symbiotic plasmid and mutation (by transposon mutagenesis) on the expression of rhi genes in Rhizobium leguminosarum biovar viciae were studied. Strains of the bacterium bearing and lacking regulatory gene rhiR were grown to late exponential phase and assayed for the production of rhi genes inducer. R. leguminosarum biovar viciae was specific for the synthesis of the rh...

A molecular characterization of uptake hydrogenase in Frankia was performed by using two-dimensional gel electrophoresis, matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry, PCR amplification and Southern blotting. A polypeptide of approx. 60 kDa was recognized in Frankia UGL011102, AVCI1 and KB5 on the two-dimensional gel by blotting with Ralstonia eutropha (Hox G) an...

A gene library of genomic DNA from the hydrogen uptake (Hup)-positive strain 128C53 of Rhizobium leguminosarum was constructed by using the broad-host-range mobilizable cosmid vector pLAFR1. The resulting recombinant cosmids contained insert DNA averaging 21 kilobase pairs (kb) in length. Two clones from the above gene library were identified by colony hybridization with DNA sequences from plas...

The rhizobia-legume, root-nodule symbiosis provides the most efficient source of biologically fixed ammonia fertilizer for agricultural crops. Its development involves pathways of specificity, infectivity, and effectivity resulting from expressed traits of the bacterium and host plant. A key event of the infection process required for development of this root-nodule symbiosis is a highly locali...