title: Conserved Endonuclease Function of Hantavirus L Polymerase.
abstract: Hantaviruses are important emerging pathogens belonging to the Bunyaviridae family. Like other segmented negative strand RNA viruses, the RNA-dependent RNA polymerase (RdRp) also known as L protein of hantaviruses lacks an intrinsic "capping activity". Hantaviruses therefore employ a "cap snatching" strategy acquiring short 5' RNA sequences bearing 5'cap structures by endonucleolytic cleavage from host cell transcripts. The viral endonuclease activity implicated in cap snatching of hantaviruses has been mapped to the N-terminal domain of the L protein. Using a combination of molecular modeling and structure-function analysis we confirm and extend these findings providing evidence for high conservation of the L endonuclease between Old and New World hantaviruses. Recombinant hantavirus L endonuclease showed catalytic activity and a defined cation preference shared by other viral endonucleases. Based on the previously reported remarkably high activity of hantavirus L endonuclease, we established a cell-based assay for the hantavirus endonuclase function. The robustness of the assay and its high-throughput compatible format makes it suitable for small molecule drug screens to identify novel inhibitors of hantavirus endonuclease. Based on the high degree of similarity to RdRp endonucleases, some candidate inhibitors may be broadly active against hantaviruses and other emerging human pathogenic Bunyaviruses.
authors.affiliation: Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland. Sylvia.Rothenberger-Aubert@chuv.ch.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Rothenberger
authors.affiliation: Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland. Giulia.Torriani@chuv.ch.
authors.forename: Giulia
authors.initials: G
authors.lastname: Torriani
authors.affiliation: SIB Swiss Institute of Bioinformatics, Lausanne CH-1015, Switzerland. maria.johansson@isb-sib.ch.
authors.forename: Maria U
authors.initials: MU
authors.lastname: Johansson
authors.affiliation: Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland. Stefan.Kunz@chuv.ch.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kunz
authors.affiliation: SPIEZ Laboratory, Austrasse, Spiez CH-3700, Switzerland. oliver.engler@babs.admin.ch.
authors.forename: Olivier
authors.initials: O
authors.lastname: Engler
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004252:DNA Mutational Analysis; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism*; D006476:Orthohantavirus / Q000201:enzymology* / Q000235:genetics; D008958:Models, Molecular; D000072417:Protein Domains; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D014764:Viral Proteins; C500570:L protein, hantavirus; D012324:RNA-Dependent RNA Polymerase; D004720:Endonucleases
keywords: Bunyaviridae; emerging diseases; endonuclease; hantavirus