Complete sequence of bluetongue virus L2 RNA that codes for the antigen recognized by neutralizing antibodies

Abstract

The complete sequence of the RNA which encodes the major outer-shell-neutralizing antigen (VP2) of bluetongue virus serotype 10 was determined from overlapping cDNA clones inserted into pBR322. The segment L2 RNA was 2,926 base pairs long (1.87 X 10(6) daltons) and had, in one strand, an open reading frame capable of coding for a protein that had a calculated size of 111,122 daltons (956 amino acids) and a +11.5 net charge. The coding strands of both the L2 gene and the group-specific L3 gene of bluetongue virus serotype 17 (M. Purdy, J. Petre, and P. Roy, J. Virol. 51:754-759, 1984) had common sequences of some six nucleotides at their 5' termini (namely, GUUAAA...) and eight nucleotides (namely, ...ACACUUAC) at their 3' termini. Both had short 5' noncoding regions with AUG codons at residues 20 to 22 (L2) and 18 to 20 (L3). The sequences flanking these AUG codons were similar (A/GCCAUGG). The 3' noncoding regions were longer (36 nucleotides for L2, 49 nucleotides for L3). The predicted amino acid sequence of the L2, compared with the similarly sized L3 gene product, was rich in cysteine residues and charged amino acids.