Mercuric reductase. Purification and characterization of a transposon-encoded flavoprotein containing an oxidation-reduction-active disulfide.
Cites background or methods from "Mercuric reductase. Purification an..."
...Low thiol titers for the proteins assayed in the original comparisons [195,196] indicate that the N-terminal cysteines were not initially reduced when the proteins were added to the assays....
...At the same time, careful reductive titrations of the wild-type protein demonstrated that most preparations required four electrons to reach a stable EH2 state (instead of the expected two electrons) and that each two electrons gave rise to the appearance of two new cysteine thiols in the protein for a total of four  rather than the two previously reported }....
...Although an analogous mechanism was considered a possibility for MerA , chemical precedent for the interaction of thiols with Hg(II) suggested a role for high-af¢nity complexation of Hg(II) by these thiols rather than a role in its reduction....
...Fox and Walsh  reported the ¢rst large-scale puri¢cation of the Tn501-encoded MerA and showed that the homodimeric enzyme exhibited spectral and biochemical properties similar to those of the pyridine nucleotide disul¢de oxidoreductase family whose most common members include glutathione reductase (GR) and lipoamide dehydrogenase....
...Thus before proceeding with further investigation of the properties of the C-terminal segment and residues in the binding pathway, the Miller lab has recently subcloned the catalytic core region of the Tn501 MerA (residues 96^ 561)  in an e¡ort to obtain homogeneous protein free of the problematic proteolysis of the full-length protein ....
Cites background from "Mercuric reductase. Purification an..."
...However, because of its high reactivity, Hg in the environment exists mainly as a divalent cation Hg2+; bacteria can catalyze the reduction of the mercuric ion to elemental Hg and enhance the volatilization abilities of associated plants (Fox & Walsh, 1982)....