The crystal structure of human hypoxanthine-guanine phosphoribosyltransferase with bound GMP Academic Article uri icon

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.

altmetric score

  • 3

author list (cited authors)

  • Eads, J. C., Scapin, G., Xu, Y., Grubmeyer, C., & Sacchettini, J. C.

citation count

  • 160

complete list of authors

  • Eads, JC||Scapin, G||Xu, Y||Grubmeyer, C||Sacchettini, JC

publication date

  • July 1994

published in