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Title
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Structure determination of a dimeric form of erabutoxin-b, crystallized from a thiocyanate solution.
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Authors
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P.Saludjian,
T.Prangé,
J.Navaza,
R.Ménez,
J.P.Guilloteau,
M.Riès-Kautt,
A.Ducruix.
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Ref.
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Acta Crystallogr B, 1992,
48,
520-531.
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PubMed id
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Abstract
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Erabutoxin-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.
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