CHE.496/2009/Planning

Strategies

 * Knockout arsA or arsB
 * Existing mutant strain: arsB758(del)::kan
 * Uncertain whether function is KO
 * Upregulate E. coli arsC (arsenate reductase)
 * Include copy of the gene on a plasmid, express at rates higher than wt
 * Transfer exogenous arsenate reductases to E.coli
 * Two families besides the E.coli arsC exist
 * Question of whether they are more efficient, require co-enzymes, etc
 * Express metal binding peptide in periplasm
 * Cys-Gly-Cys-Cys-Gly repeat + fusion to maltose binding protein for localization
 * Development of Bacterium-Based Heavy Metal Biosorbents: Enhanced Uptake of Cadmium and Mercury by Escherichia coli Expressing a Metal Binding Motif
 * Try to get the arsenic incorporated into a compound / complex
 * Potentially able to precipitate out of solution?

Pathway


Genes

 * arsA
 * Arsenical pump-driving ATPase [ Escherichia coli UMN026 ]
 * GeneID: 7155799


 * arsB
 * arsenite/antimonite transporter [ Escherichia coli str. K-12 substr. DH10B ]
 * GeneID: 6062297


 * arsC
 * arsenate reductase [ Escherichia coli str. K-12 substr. DH10B ]
 * GeneID: 6058451
 * Protein: Arsenate Reductase (ArsC) family, ArsC subfamily; arsenic reductases similar to that encoded by arsC on the R733 plasmid of Escherichia coli. E. coli ArsC catalyzes the reduction of arsenate [As(V)] to arsenite [As(III)], the first step in the detoxification of arsenic, using reducing equivalents derived from glutathione (GSH) via glutaredoxin (GRX). ArsC contains a single catalytic cysteine, within a thioredoxin fold, that forms a covalent thiolate-As(V) intermediate, which is reduced by GRX through a mixed GSH-arsenate intermediate. This family of predominantly bacterial enzymes is unrelated to two other families of arsenate reductases which show similarity to low-molecular-weight acid phosphatases and phosphotyrosyl phosphatases.