Analyses of the complete sequence of the genome of wheat Eqlid mosaic virus, a novel species in the genus Tritimovirus

摘要

The complete nucleotide sequence of the genome of wheat Eqlid mosaic virus (WEqMV) (excluding the poly A tail) comprised 9636 nucleotides including 5′ and 3′ noncoding regions of 137 and 172 nt, respectively. It contained a single ORF coding for a polyprotein of 3,109 amino acid residues and had a deduced genome organization typical of members of the family Potyviridae and with proteinase cleavage sites very similar to those of the members of the genus Tritimovirus. Pairwise and multiple alignments and phylogenetic analysis showed that WEqMV is a distinct species in the genus Tritimovirus. WEqMV and Wheat streak mosaic virus (WSMV) shared the greatest nucleotide sequence identity in the NIb and HC-Pro cistrons (63.2% and 60.8%, respectively) and the lowest sequence identity in the P1 and CP cistrons (51.2% and 51.1%, respectively). Sequence identity for the complete genome of WEqMV and WSMV was 56.8% at the nucleotide level and 50.7% at the amino acid level. WEqMV had 57.2% nucleotide identity and 50.6% amino acid identity with Oat necrotic mottle virus and 52.5% nucleotide identity and 45.5% amino acid identity with Brome streak mosaic virus. The relationship of WEqMV with other members of the family Potyviridae was more distant. Structural analysis of WEqMV protein showed presence of potential transmembrane helices in 6k1, 6k2, and P3 proteins.