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HIGH-RESOLUTION STRUCTURES OF ADENYLATE KINASE FROM YEAST LIGATED WITH INHIBITOR AP5A, SHOWING THE PATHWAY OF PHOSPHORYL TRANSFERHIGH-RESOLUTION STRUCTURES OF ADENYLATE KINASE FROM YEAST LIGATED WITH INHIBITOR AP5A, SHOWING THE PATHWAY OF PHOSPHORYL TRANSFER
Structural highlights
Function[KAD2_YEAST] Catalyzes the reversible transfer of the terminal phosphate group between ATP and AMP. Plays an important role in cellular energy homeostasis and in adenine nucleotide metabolism. Adenylate kinase activity is critical for regulation of the phosphate utilization and the AMP de novo biosynthesis pathways.[HAMAP-Rule:MF_03168][1] [2] [3] 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 structure of adenylate kinase from yeast ligated with the two-substrate-mimicking inhibitor Ap5A and Mg2+ has been refined to 1.96 A resolution. In addition, the refined structure of the same complex with a bound imidazole molecule replacing Mg2+ has been determined at 1.63 A. These structures indicate that replacing Mg2+ by imidazole disturbs the water structure and thus the complex. A comparison with the G-proteins shows that Mg2+ is exactly at the same position with respect to the phosphates. However, although the Mg2+ ligand sphere of the G-proteins is a regular octahedron containing peptide ligands, the reported adenylate kinase has no such ligands and an open octahedron leaving space for the Mg2+ to accompany the transferred phosphoryl group. A superposition of the known crystalline and therefore perturbed phosphoryl transfer geometries in the adenylate kinases demonstrates that all of them are close to the start of the forward reaction with bound ATP and AMP. Averaging all observed perturbed structures gives rise to a close approximation of the transition state, indicating in general how to establish an elusive transition state geometry. The average shows that the in-line phosphoryl transfer is associative, because there is no space for a dissociative metaphosphate intermediate. As a side result, the secondary dipole interaction in the alpha-helices of both protein structures has been quantified. High-resolution structures of adenylate kinase from yeast ligated with inhibitor Ap5A, showing the pathway of phosphoryl transfer.,Abele U, Schulz GE Protein Sci. 1995 Jul;4(7):1262-71. PMID:7670369[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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