Molecular characterization of the genes coding for glycoprotein and L protein of lymphocytic choriomeningitis virus strain MX.

Lymphocytic choriomeningitis virus (LCMV) is the prototype Arenavirus with ambisense coding strategy. We have previously described a new MX strain LCMV and determined the primary structure of the genes coding for the nucleoprotein and RING finger Z protein. In this report, we describe amplification and sequencing of the entire coding sequences of additional MX genes, the glycoprotein precursor (GPC) and L protein. The obtained MX GPC cDNA sequence was 1,615 nucleotides long and contained an ORF, which encodes the GPC precursor of 498 amino acids. MX L polymerase cDNA sequence was 6,668 nucleotides long and predicted ORF encodes the L polymerase of 2,209 amino acids. Nucleotide and deduced amino acid sequences were compared with the known GPC and L sequences and the comparison revealed that both genes shared the highest amino acid identity with Armstrong strain. Phylogenetic analysis confirmed that MX represents a separate LCMV strain. The GPC and L genes products contained several characteristic conserved regions. On the other hand, we have observed numerous differences in predicted protein sequences, which distinguish MX LCMV from other LCMV strains and might be of potential biological significance.