An N-Terminal Region of Lassa Virus L Protein Plays a Critical Role in Transcription but Not Replication of the Virus Genome

• DOI: 10.1128/jvi.01657-09
• Publication Date: 2009-12-10T01:55:14Z
• Authors: Michaela Lelke; Linda Brunotte; Carola Busch; Stephan Günther
• Keywords: Replicon; Lassa virus; Transcription; RNA polymerase II

ABSTRACT The central domain of the 200-kDa Lassa virus L protein is a putative RNA-dependent RNA polymerase. N- and C-terminal domains may harbor enzymatic functions important for viral mRNA synthesis, including capping enzymes or cap-snatching endoribonucleases. In present study, we have employed large-scale mutagenesis approach to map functionally relevant residues in these regions. main targets were acidic (Asp Glu) basic (Lys Arg) known form catalytic binding sites A total 149 different mutants generated tested replicon system. Nearly 25% evolutionarily highly conserved side chains dispensable function context. vast majority remaining had defects both transcription replication. Seven (Asp-89, Glu-102, Asp-119, Lys-122, Asp-129, Glu-180, Arg-185) selectively synthesis. phenotype was particularly pronounced Asp-89, which indispensable but could be replaced by variety amino acid without affecting genome Bioinformatics disclosed remote similarity this region type IIs endonucleases. complemented experiments with polymerase II inhibitor α-amanitin, demonstrating dependence from cellular pool. conclusion, paper describes an N-terminal being mRNA, not cell biological lend support hypothesis that part enzyme.