PRIMARY STRUCTURE OF THE LARGE (L) RNA SEGMENT OF NEPHROPATHIA EPIDEMICA VIRUS-STRAIN HALLNAS B1 CODING FOR THE VIRAL-RNA POLYMERASE

The L RNA segment of the nephropathia epidemica virus (NEV) strain Hällnäs B1 was characterized by molecular cloning of the corresponding cDNA and subsequent determination of the DNA nucleotide sequence. The L RNA segment is 6550 nucleotides long with complementarity of 20 bases at the 3′ and 5′ termini. The viral messenger sense RNA contains one major open reading frame (ORF) with a coding capacity of 2156 amino acid residues encoding a protein with a calculated molecular weight of 246 kDa and an IEP of pH 7.4. Comparison of the deduced amino acid sequences from NEV hantavirus and Bunyamwera virus (BWV) L segment messenger sense RNAs, revealed a high degree of diversity (overall amino acid identity, 17%). However, three clusters of 30-40% amino acid identity were detected. One of these domains, containing an Asp-Asp motif found in many RNA polymerases, also shares amino acid sequence homology with the PB1 polymerase component of influenza virus type A. These results indicate that the L RNA segment of NEV codes for the viral RNA-dependent RNA polymerase. The data presented here complete our previous studies on the characterization of the NEV genome by cDNA sequencing of the viral M and S RNA segments. © 1991.