1acj | pdb_00001acj

QUATERNARY LIGAND BINDING TO AROMATIC RESIDUES IN THE ACTIVE-SITE GORGE OF ACETYLCHOLINESTERASE

spinqualitylabelsall models 1acj, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1acj is a 1 chain structure with sequence from Pacific electric ray. The June 2004 RCSB PDB Molecule of the Month feature on Acetylcholinesterase by David S. Goodsell is 10.2210/rcsb_pdb/mom_2004_6. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: THA Activity: Acetylcholinesterase, with EC number 3.1.1.7 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [ACES_TORCA] Terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft. May be involved in cell-cell interactions. 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 PubMed Binding sites of Torpedo acetylcholinesterase (EC 3.1.1.7) for quaternary ligands were investigated by x-ray crystallography and photoaffinity labeling. Crystal structures of complexes with ligands were determined at 2.8-A resolution. In a complex with edrophonium, and quaternary nitrogen of the ligand interacts with the indole of Trp-84, and its m-hydroxyl displays bifurcated hydrogen bonding to two members of the catalytic triad, Ser-200 and His-440. In a complex with tacrine, the acridine is stacked against the indole of Trp-84. The bisquaternary ligand decamethonium is oriented along the narrow gorge leading to the active site; one quaternary group is apposed to the indole of Trp-84 and the other to that of Trp-279, near the top of the gorge. The only major conformational difference between the three complexes is in the orientation of the phenyl ring of Phe-330. In the decamethonium complex it lies parallel to the surface of the gorge; in the other two complexes it is positioned to make contact with the bound ligand. This close interaction was confirmed by photoaffinity labelling by the photosensitive probe 3H-labeled p-(N,N-dimethylamino)benzenediazonium fluoroborate, which labeled, predominantly, Phe-330 within the active site. Labeling of Trp-279 was also observed. One mole of label is incorporated per mole of AcChoEase inactivated, indicating that labeling of Trp-279 and that of Phe-330 are mutually exclusive. The structural and chemical data, together, show the important role of aromatic groups as binding sites for quaternary ligands, and they provide complementary evidence assigning Trp-84 and Phe-330 to the "anionic" subsite of the active site and Trp-279 to the "peripheral" anionic site. Quaternary ligand binding to aromatic residues in the active-site gorge of acetylcholinesterase.,Harel M, Schalk I, Ehret-Sabatier L, Bouet F, Goeldner M, Hirth C, Axelsen PH, Silman I, Sussman JL Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):9031-5. PMID:8415649 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also AChE inhibitors and substrates Acetylcholinesterase Acetylcholinesterase complexed with N-9-(1'%2C2'%2C3'%2C4'-tetrahydroacridinyl)-1%2C8-diaminooctane Torpedo Californica Acetylcholinesterase in complex with an (R)-Tacrine-(10)-Hupyridone inhibitor Torpedo californica acetylcholinesterase with alkylene-linked tacrine dimer (5 carbon linker) Torpedo californica acetylcholinesterase with alkylene-linked tacrine dimer (7 carbon linker) 3D structures of acetylcholinesterase

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OCA, Joel L. Sussman