title: Expression, purification and crystallization of VP4 protease from Tellina virus 1.
abstract: Tellina virus 1 is an aquabirnavirus that was isolated from the sand-dwelling marine bivalve mollusc Tellina tenuis. The self-encoded protease viral protein 4 (VP4) processes its own polyprotein to yield the individual proteins VP2 and VP3 that are required for viral assembly. VP4 protease utilizes a serine-lysine catalytic dyad in its mechanism. A full-length VP4 construct was overexpressed in Escherichia coli and purified to homogeneity using nickel-affinity chromatography. Ion-exchange and size-exclusion chromatographic steps were utilized to isolate a monomeric fraction of the protein. The purified monomeric VP4 was subjected to limited proteolysis to yield crystallizable protein. Crystal growth was performed using the hanging-drop vapour-diffusion method and was carried out at room temperature (∼296 K). Hexagonal crystals grew in the presence of PEG 8000, ammonium sulfate and urea. These crystals diffracted to beyond 2.1 Å resolution and belonged to space group P6(4)22, with unit-cell parameters a=59.1, b=59.1, c=208.1 Å, one molecule in the asymmetric unit and a solvent content of 42%.
authors.affiliation: Department of Molecular Biology and Biochemistry, Simon Fraser University, South Science Building, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Ivy Yeuk Wah
authors.initials: IY
authors.lastname: Chung
authors.forename: Mark
authors.initials: M
authors.lastname: Paetzel
mesh_terms: D000818:Animals; D019201:Aquabirnavirus / Q000201:enzymology*; D049872:Bivalvia / Q000821:virology; D003460:Crystallization; D018360:Crystallography, X-Ray; D004279:DNA, Viral; D008969:Molecular Sequence Data; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins; D012697:Serine Endopeptidases; C414992:VP4 protease, birnavirus