UNLABELLED The trxB2 gene, which is annotated as a thioredoxin reductase, was found to be essential for growth of Lactococcus lactis in the presence of oxygen. The corresponding protein (TrxB2) showed a high similarity with Bacillus subtilis YumC (E value = 4.0E-88), and YumC was able to fully complement the ΔtrxB2 mutant phenotype. YumC represents a novel type of ferredoxin (flavodoxin) reduct...

Ferredoxin, flavodoxin, and rubredoxin were purified to homogeneity from Clostridium formicoaceticum and characterized. Variation of the iron concentration of the growth medium caused substantial changes in the concentrations of ferredoxin and flavodoxin but not of rubredoxin. The ferredoxin has a molecular weight of 6,000 and is a four iron-four sulfur protein with eight cysteine residues. The...

A [CO]HN(CA)CB-E.COSY pulse scheme is described for measurement of three-bond couplings, 3JC'C beta, between carbonyl and aliphatic C beta carbons in ubiquitin, uniformly enriched with 13C and 15N. A Karplus relation, 3JC'C beta = 1.28 cos2(phi - 120 degrees) -1.02 cos(phi - 120 degrees) + 0.30 Hz, is obtained by correlating the 3JC'C beta values measured for human ubiquitin with backbone phi a...

Iron (Fe) availability restricts diatom growth and primary production in large areas of the oceans. It is a challenge to assess the bulk Fe nutritional health of natural diatom populations, since species can differ in their physiological and molecular responses to Fe limitation. We assayed expression of selected genes in diatoms from the Thalassiosira genus to assess their potential utility as ...

somatic embryos of persian walnut were transformed with two strains of agrobacterium tumefaciens i.e. lba4404 and c58, and two plasmids, namely, pbi121 with nptii and gus genes for improving the transformation protocol, and p6u-ubi-fvti plasmid containing the hpt and fld genes. the transformation frequency was 10%. pcr and rt-pcr analysis proved the presence and expression of the genes. the tra...

FMN and flavodoxin, when reduced by the action of ferredoxin-TPN+ oxidoreductase, have been shown to cause both univalent and divalent reductions of oxygen. Superoxide radicals, so generated, were detected by their abilities to oxidize epinephrine to adrenochrome and to reduce cytochrome c. Superoxide dismutase inhibited these actions of the superoxide radical. The ratio of the univalent reduct...

The influence of the amino acid residues surrounding the flavin ring in the flavodoxin of the cyanobacterium Anabaena PCC 7119 on the electron spin density distribution of the flavin semiquinone was examined in mutants of the key residues Trp(57) and Tyr(94) at the FMN binding site. Neutral semiquinone radicals of the proteins were obtained by photoreduction and examined by electron-nuclear dou...

Oxidative stress in plants causes ferredoxin down-regulation and NADP(+) shortage, over-reduction of the photosynthetic electron transport chain, electron leakage to oxygen and generation of reactive oxygen species (ROS). Expression of cyanobacterial flavodoxin in tobacco chloroplasts compensates for ferredoxin decline and restores electron delivery to productive routes, resulting in enhanced s...