On the role of Glu-68 in alcohol dehydrogenase.
Theoretical computations (molecular dynamics and combined quantum chemical and molecular mechanical geometry optimizations) have been performed on horse liver alcohol dehydrogenase. The results provide evidence that Glu-68, a highly conserved residue located 0.47 nm from the catalytic zinc ion, may intermittently coordinate to the zinc ion. Structures with Glu-68 coordinated to the zinc ion are almost as stable as structures with Glu-68 at the crystal position and the barrier between the two configurations of Glu-68 is so low that it can readily be bypassed at room temperature. There is a cavity behind the zinc ion that seems to be tailored to allow such coordination of Glu-68 to the zinc ion. It is suggested that Glu-68 may facilitate the exchange of ligands in the substrate site by coordinating to the zinc ion when the old ligand dissociates.
Ryde
U
U
Department of Theoretical Chemistry, University of Lund, Sweden.
D000426:Alcohol Dehydrogenase / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003198:Computer Simulation; D017124:Conserved Sequence; D018698:Glutamic Acid / Q000737:chemistry*; D006736:Horses; D008099:Liver / Q000201:enzymology; D008958:Models, Molecular; D015032:Zinc / Q000737:chemistry*
D018698:Glutamic Acid; D000426:Alcohol Dehydrogenase; D015032:Zinc