Biochemistry major Victor Gutierrez-Schultz is continuing work on an ongoing project to clone the genes for the enzyme arsenite oxidase into E. coli, and induce these bacteria into making the enzyme in an environmentally friendly manner. This enzyme has the potential to be used in water purification methods to remove arsenic from groundwater. The original host, Alcaligenes faecalis, makes the arsenite oxidase enzyme only when the growth medium contains the arsenite so that growing A. faecalis to isolate the enzyme generates many 55 gallon drums of arsenic-containing toxic waste. By transferring the genes into E. coli, Victor will induce expression of the protein IPTG, a non-toxic inducer of the lac operon. Previous attempts at cloning the arsenite oxidase genes into E. coli generated new mutations, which could affect the structure and activity of the enzyme. Victor is repairing the introduced mutations through site-specific mutagenesis. Subsequent experiments will aim to find the best conditions for inducing enzyme synthesis, correctly folding the two subunits of the enzyme, and properly inserting the [3F-4S] cluster, the molybdopterin cofactor, and the [2Fe-2S] Rieske center into the enzyme. Congratulations to Victor for being awarded a SMART grant to support his summer research with Dr. Anderson.
