title: Structure determination of a dimeric form of erabutoxin-b, crystallized from a thiocyanate solution.
abstract: 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.
authors.affiliation: Chimie Structurale Bio-moléculaire (URA 1430 CNRS), UFR Biomédicale, Bobigny, France.
authors.forename: P
authors.initials: P
authors.lastname: Saludjian
authors.forename: T
authors.initials: T
authors.lastname: Prangé
authors.forename: J
authors.initials: J
authors.lastname: Navaza
authors.forename: R
authors.initials: R
authors.lastname: Ménez
authors.forename: J P
authors.initials: JP
authors.lastname: Guilloteau
authors.forename: M
authors.initials: M
authors.lastname: Riès-Kautt
authors.forename: A
authors.initials: A
authors.lastname: Ducruix
mesh_terms: D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D004870:Erabutoxins / Q000737:chemistry*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011487:Protein Conformation; D012984:Software; D012996:Solutions; D013861:Thiocyanates / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D046911:Macromolecular Substances; D012996:Solutions; D013861:Thiocyanates; D004870:Erabutoxins; C031760:thiocyanate