title: Molecular characterization of the African orthobunyavirus Ilesha virus.
abstract: Ilesha virus is an arthropod-borne virus belonging to the genus Orthobunyavirus of the Bunyaviridae family. Ilesha virus has been isolated from humans in several African countries, mostly in relation with febrile illness and erythema, though there are reported cases of fatal meningoencephalitis and hemorrhagic fever. In the present study, we report the complete genomic sequence of all three Ilesha virus segments (S, M, L) and characterize the open reading frames. The nucleoprotein encoded by segment S contains 59 conserved orthobunyavirus amino acids putatively critical for protein function. For the polyprotein encoded by segment M, potential proteolytic cleavage sites and N-glycosylation sites as well as conserved cysteines are described in reference to other orthobunyaviruses. Within the C terminal glycoprotein Gc a putative fusion peptide could be localized. In the RNA-dependent RNA polymerase encoded by segment L, all strictly conserved amino acids within the four conserved regions known to be catalytically active are present. Phylogenetic analyses conducted for each Ilesha virus genomic segment confirm the classification of Ilesha virus within the Bunyamwera serogroup of orthobunyaviruses. Ilesha virus segments S and L exhibit highest genetic conservation with Bunyamwera virus and Ngari virus, with maximum sequence identities of 88% for segment S and 82% for segment L. However, the M segment was found to be more diverse with a maximum nucleotide identity of 72% to Bunyamwera serogroup viruses.
authors.affiliation: Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria. Electronic address: karin.pachler@vetmeduni.ac.at.
authors.forename: Karin
authors.initials: K
authors.lastname: Pachler
authors.forename: Daniel
authors.initials: D
authors.lastname: Růžek
authors.forename: Norbert
authors.initials: N
authors.lastname: Nowotny
mesh_terms: D000349:Africa; D000595:Amino Acid Sequence; D001483:Base Sequence; D002044:Bunyaviridae Infections / Q000821:virology*; D016679:Genome, Viral / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000235:genetics; D016851:Orthobunyavirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014760:Viral Fusion Proteins / Q000235:genetics
chemical_list: D019590:Nucleocapsid Proteins; D012367:RNA, Viral; D014760:Viral Fusion Proteins; D012324:RNA-Dependent RNA Polymerase
keywords: BATV; BUNV; Batai virus; Bunyamwera virus; CEV; CVV; Cache Valley virus; California encephalitis virus; GERV; Gc; Genome characterization; Germiston virus; Gn; ILEV; Ilesha virus; L; LACV; La Crosse virus; M; MAGV; MBOV; Maguari virus; Mboke virus; N; NRIV; NSm; NSs; Ngari virus; ORF; Orthobunyavirus; Phylogenetic analysis; RNA-dependent RNA polymerase; RdRP; S; TAHV; TENV; Tahyna virus; Tensaw virus; envelope glycoprotein; large segment; medium segment; nonstructural protein encoded by M segment; nonstructural protein encoded by S segment; nucleocapsid protein; open reading frame; small segment