The Zn inactive class of glyoxalase I (Glo1) enzymes are metalloenzymes that are typically homodimeric with two metal-dependent active sites. While the two active sites share identical amino acid composition, this class of enzyme is optimally active with only one metal per homodimer. We have determined the X-ray crystal structure of GloA2, one of the Zn inactive Glo1 enzymes from Pseudomonas aeruginosa. The presented structures exhibit an unprecedented metal-binding arrangement consistent with half-of-sites activity: one active site contains a single activating Ni2+ ion while the other contains two inactivating Zn2+ ions.
Students from UWA CHEM3007 Undergraduate Unit helped with some of the data collection.