Crystal structures of the G139A, G139A-NO and G143H mutants of human heme oxygenase-1. A finely tuned hydrogen-bonding network controls oxygenase versus peroxidase activity.
Lad, L., Koshkin, A., Ortiz de Montellano, P.R., Poulos, T.L.(2005) J Biol Inorg Chem 10: 138-146
- PubMed: 15690204 
- DOI: 10.1007/s00775-004-0620-6
- Primary Citation of Related Structures:  
1XJZ, 1XK0, 1XK1 - PubMed Abstract: 
Conserved glycines, Gly139 and Gly143, in the distal helix of human heme oxygenase-1 (HO-1) provide the flexibility required for the opening and closing of the heme active site for substrate binding and product dissociation during HO-1 catalysis. Earlier mutagenesis work on human HO-1 showed that replacement of either Gly139 or Gly143 suppresses heme oxygenase activity and, in the case of the Gly139 mutants, increases peroxidase activity (Liu et al ...