title: Preparation and X-ray crystallographic analysis of recombinant obelin crystals diffracting to beyond 1.1 A.
abstract: Crystals of recombinant obelin, the Ca(2+)-regulated photoprotein from the marine hydroid Obelia longissima, have been grown from a solution containing PEG 8000 and potassium phosphate. Hexaminecobalt trichloride was used as an additive to increase the chance of crystallization. The crystals grow in a light yellow cubic form (0.5 x 0.5 x 0.45 mm) which diffracts to beyond 1.1 A resolution. The crystals belong to the space group C2, with unit-cell parameters a = 83.43, b = 54.92, c = 52.99 A, beta = 112.00 degrees. The asymmetric unit contains one molecule. Crystals exposed to calcium ion before and after X-ray irradiation emit light, confirming that the crystals consist of an active photoprotein.
authors.affiliation: Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036, Russia.
authors.forename: E S
authors.initials: ES
authors.lastname: Vysotski
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Rose
authors.forename: B C
authors.initials: BC
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Lee
mesh_terms: D000818:Animals; D003063:Cnidaria / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D008164:Luminescent Proteins / Q000737:chemistry* / Q000302:isolation & purification; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D008164:Luminescent Proteins; D011994:Recombinant Proteins; C010497:obelin