Disease relevance of DVU2680

• The gene coding for the flavodoxin protein from Desulfovibrio vulgaris (Hildenborough) has been identified, cloned, and sequenced [1].
• To our knowledge, this is the first example of the expression of a foreign flavodoxin gene in E. coli using recombinant DNA methods [1].
• Azotobacter vinelandii flavodoxin reacts with reduced D. vulgaris cytochrome c3 in a slow, monophasic manner with limiting rate of electron transfer of 1.2 +/- 0.06 s-1 and a Kd value of 80.9 +/- 10.7 microM [2].

High impact information on DVU2680

• Cloning, nucleotide sequence, and expression of the flavodoxin gene from Desulfovibrio vulgaris (Hildenborough) [1].
• Amino acid sequence of Desulfovibrio vulgaris flavodoxin [3].
• 1H, 13C and 15N assignment of the hydroquinone form of flavodoxin from Desulfovibrio vulgaris (Hildenborough) and comparison of the chemical shift differences with respect to the oxidized state [4].
• Evaluation of the electrostatic effect of the 5'-phosphate of the flavin mononucleotide cofactor on the oxidation--reduction potentials of the flavodoxin from desulfovibrio vulgaris (Hildenborough) [5].
• The cumulative electrostatic effect of aromatic stacking interactions and the negative electrostatic environment of the flavin mononucleotide binding site is a major determinant of the reduction potential for the flavodoxin from Desulfovibrio vulgaris [Hildenborough] [6].

Chemical compound and disease context of DVU2680

• Sequence-specific 1H and 15N resonance assignments have been made for all 145 non-prolyl residues and for the flavin cofactor in oxidized Desulfovibrio vulgaris flavodoxin [7].
• Effects of substituting asparagine for glycine-61 in flavodoxin from Desulfovibrio vulgaris (Hildenborough) [8].

Biological context of DVU2680

• One recombinant, carrying a 1.6-kilobase (kb) insert which strongly hybridizes to the probe, was found to contain a nucleotide sequence which codes for the first 104 residues of the amino-terminal portion of the flavodoxin protein sequence but lacked the remainder of the gene [1].
• This study provides further support for the concept that the cumulative effect of the unfavorable electrostatic interactions introduced by coplanar aromatic or pi-pi stacking interactions and the negative electrostatic environment of the FMN binding site is a major determinant of the low one-electron reduction potential of the flavodoxin [6].
• A 1.4-kb PstI-HindIII fragment was ultimately identified which contains an open reading frame coding for a polypeptide of 146 amino acid residues that was highly homologous to the D. vulgaris flavodoxin, sharing a sequence identity of 55% [9].

Associations of DVU2680 with chemical compounds

• The ability to bind riboflavin distinguishes this flavodoxin from other short-chain flavodoxins which require the phosphate of FMN for flavin binding [10].
• In this study, a flavodoxin mutant was generated in which an alanine was substituted for Tyr98 while at the same time the negative electrostatic surface was partially neutralized by the substitution of the six acidic amino acid residues with their amide equivalents [6].

Enzymatic interactions of DVU2680

• Flavodoxin neutral semiquinone and oxidized cytochrome c3 are the only observable products of the reaction [2].

Other interactions of DVU2680

• This grid was incubated sequentially to identify lambda clones containing the gene for redox proteins of known amino acid sequence: cytochrome c3 (one 18-mer----four clones), flavodoxin (one 17-mer and one 26-mer----one clone) and rubredoxin (one 44-mer----21 clones) [11].
• The kinetic properties of the electron-transfer process between reduced Desulfovibrio vulgaris cytochrome c3 and D. vulgaris flavodoxin have been studied by anaerobic stopped-flow techniques [2].
• For complexes between flavodoxin and cytochrome c553 this was not the case and a lower correlation was observed between electron tunnelling coupling factors and excess energies [12].

Analytical, diagnostic and therapeutic context of DVU2680

• Site-directed mutagenesis of tyrosine-98 in the flavodoxin from Desulfovibrio vulgaris (Hildenborough): regulation of oxidation-reduction properties of the bound FMN cofactor by aromatic, solvent, and electrostatic interactions [13].
• Anaerobic titrations of reduced cytochrome c3 with oxidized flavodoxin show a stoichiometry of 4 mol of flavodoxin required to oxidize the tetraheme cytochrome [2].

References