title: Purification and crystallization of Kokobera virus helicase.
abstract: Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. The flavivirus genus is characterized by a positive-sense single-stranded RNA genome. The unique open reading frame of the viral RNA is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the NS3 gene that encodes a C-terminal helicase domain consisting of 431 amino acids. Helicase inhibitors are potential antiviral drugs as the helicase is essential to viral replication. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method. The crystals belong to space group P3(1)21 (or P3(2)21), with unit-cell parameters a = 88.6, c = 138.6 A, and exhibit a diffraction limit of 2.3 A.
authors.affiliation: Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: De Colibus
authors.forename: Silvia
authors.initials: S
authors.lastname: Speroni
authors.forename: Bruno
authors.initials: B
authors.lastname: Coutard
authors.forename: Naomi L
authors.initials: NL
authors.lastname: Forrester
authors.forename: Ernest
authors.initials: E
authors.lastname: Gould
authors.forename: Bruno
authors.initials: B
authors.lastname: Canard
authors.forename: Andrea
authors.initials: A
authors.lastname: Mattevi
mesh_terms: D003460:Crystallization; D005416:Flavivirus / Q000201:enzymology*; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000737:chemistry* / Q000302:isolation & purification; D014764:Viral Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D014764:Viral Proteins; D020365:RNA Helicases