1arg
Aspartate aminotransferase, phospho-5'-pyridoxyl aspartate complexAspartate aminotransferase, phospho-5'-pyridoxyl aspartate complex
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe electron distribution in the coenzyme-substrate adduct of aspartate aminotransferase was changed by replacing active-site Arg386 with alanine and introducing a new arginine residue nearby. [Y225R, R386A]Aspartate aminotransferase decarboxylates L-aspartate to L-alanine (kcat = 0.04 s-1), while its transaminase activity towards dicarboxylic amino acids is decreased by three orders of magnitude (kcat = 0.19 s-1). Molecular-dynamics simulations based on the crystal structure of the mutant enzyme suggest that a new hydrogen bond to the imine N atom of the pyridoxal-5'-phosphate- aspartate adduct and an altered electrostatic potential around its beta-carboxylate group underlie the 650,000-fold increase in the ratio of beta-decarboxylase/transaminase activity. Changing the reaction specificity of a pyridoxal-5'-phosphate-dependent enzyme.,Graber R, Kasper P, Malashkevich VN, Sandmeier E, Berger P, Gehring H, Jansonius JN, Christen P Eur J Biochem. 1995 Sep 1;232(2):686-90. PMID:7556224[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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