Characterization of Protein Chemistry, Perchlorate Reduction

crystal structure of perchlorate reductase enzyme

Perchlorate Reductase

Perchlorate reductase (Pcr) catalyzes the 2e- reduction of perchlorate to chlorate as well as the subsequent 2e- reduction of chlorate to chlorite during respiration by dissimilatory (per)chlorate reducing bacteria (DPRB). 

Shown in blue is the predicted crystal structure of the α-subunit of perchlorate reductase (PcrA) based upon the published crystal structures nitrate reductase (NarG) and ethylbenzene dehydrogenase (EbdA), both of which have 34% identity to PcrA. 

The substrate/product tunnel (shown in white) to the buried molybdopterin bis-guanine dinucleotide (MGD) cofactor which acts as the putative active site was computed.

Currently, point-mutants of PcrA are being constructed to change relatively small residues that line the tunnel to tryptophan residues in order to potentially block the tunnel and validate the computed model.