6ebx
From Proteopedia
STRUCTURE DETERMINATION OF A DIMERIC FORM OF ERABUTOXIN B, CRYSTALLIZED FROM THIOCYANATE SOLUTION
Structural highlights
Function[NXSB_PSSEM] Binds with high affinity to muscular nicotinic acetylcholine receptors (nAChRs), and with low affinity to neuronal alpha-7 nAChRs and inhibit acetylcholine from binding to the receptor, thereby impairing neuromuscular transmission. Produces peripheral paralysis by blocking neuromuscular transmission at the postsynaptic site.[1] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedErabutoxin-b, M(r) = 6861.1, a single 62 amino-acid chain folded by four disulfide bridges, was crystallized in a new orthorhombic form by using thiocyanate as crystallizing agent. The space group is P2(1)2(1)2(1) with a = 53.36 (4), b = 40.89 (4), c = 55.71 (5) A, V = 121533.1 A and Z = 8. X-ray diffraction data were recorded at the LURE synchrotron facility (lambda = 1.405 A). The structure was solved by molecular replacement and shows a dimeric association through an anti-parallel beta-sheet around the twofold non-crystallographic axis. The two independent molecules, one SCN- ion and 97 associated water molecules were refined by molecular dynamics and annealing techniques to R = 19.6% (10,913 Fobs, resolution 5-1.7 A). The thiocyanate ion is located at the interface of the dimer and close to the non-crystallographic twofold axis. Structure determination of a dimeric form of erabutoxin-b, crystallized from a thiocyanate solution.,Saludjian P, Prange T, Navaza J, Menez R, Guilloteau JP, Ries-Kautt M, Ducruix A Acta Crystallogr B. 1992 Aug 1;48 ( Pt 4):520-31. PMID:1418823[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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