The crystal structure of human hypoxanthine-guanine phosphoribosyltransferase with bound GMP.Eads, J.C., Scapin, G., Xu, Y., Grubmeyer, C., Sacchettini, J.C.
(1994) Cell 78: 325-334
- PubMed: 8044844
- DOI: https://doi.org/10.1016/0092-8674(94)90301-8
- Primary Citation of Related Structures:
- PubMed Abstract:
The crystal structure of HGPRTase with bound GMP has been determined and refined to 2.5 A resolution. The enzyme has a core alpha/beta structure resembling the nucleotide-binding fold of dehydrogenases, and a second lobe composed of residues from the amino and carboxy termini. The GMP molecule binds in an anti conformation in a solvent-exposed cleft of the enzyme. Lys-165, which forms a hydrogen bond to O6 of GMP, appears to be critical for determining the specificity for guanine and hypoxanthine over adenine. The location of active site residues also provides evidence for a possible mechanism for general base-assisted HGPRTase catalysis. A rationalization of the effects on stability and activity of naturally occurring single amino acid mutations of HGPRTase is presented, including a discussion of several mutations at the active site that lead to Lesch-Nyhan syndrome.
Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461.