title: Preliminary crystallographic characterization of an RNA helicase from Kunjin virus.
abstract: Kunjin virus is a member of the Flavivirus genus and is an Australian variant of West Nile virus. The C-terminal domain of the Kunjin virus NS3 protein displays helicase activity. The protein is thought to separate daughter and template RNA strands, assisting the initiation of replication by unwinding RNA secondary structure in the 3' nontranslated region. Expression, purification and preliminary crystallographic characterization of the NS3 helicase domain are reported. It is shown that Kunjin virus helicase may adopt a dimeric assembly in absence of nucleic acids, oligomerization being a means to provide the helicases with multiple nucleic acid-binding capability, facilitating translocation along the RNA strands. Kunjin virus NS3 helicase domain is an attractive model for studying the molecular mechanisms of flavivirus replication, while simultaneously providing a new basis for the rational development of anti-flaviviral compounds.
authors.affiliation: Department of Biomolecular Sciences and Biotechnology, CNR-INFM, University of Milano, Via Celoria 26, 20133 Milano, Italy.
authors.forename: Eloise
authors.initials: E
authors.lastname: Mastrangelo
authors.forename: Michela
authors.initials: M
authors.lastname: Bollati
authors.forename: Mario
authors.initials: M
authors.lastname: Milani
authors.forename: Nadège
authors.initials: N
authors.lastname: Brisbarre
authors.forename: Xavier
authors.initials: X
authors.lastname: de Lamballerie
authors.forename: Bruno
authors.initials: B
authors.lastname: Coutard
authors.forename: Bruno
authors.initials: B
authors.lastname: Canard
authors.forename: Alexander
authors.initials: A
authors.lastname: Khromykh
authors.forename: Martino
authors.initials: M
authors.lastname: Bolognesi
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D017434:Protein Structure, Tertiary / Q000235:genetics; D021381:Protein Transport / Q000235:genetics; D020365:RNA Helicases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014902:West Nile virus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D020365:RNA Helicases; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C060028:NS3 protein, flavivirus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases