The genome structure of kyuri green mottle mosaic tobamovirus and its comparison with that of cucumber green mottle mosaic tobamovirus

The genome of the Y strain of kyuri green mottle mosaic virus (KGMMV-Y) has been completely sequenced. Its genomic structure and sequence show it to be a typical tobamovirus, that is closest to, but distinct from, that of cucumber green mottle mosaic tobamovirus (CGMMV). The genomic sequence of KGMMV-Y was compared in detail with that of the SH strain of CGMMV. The sequences of their 5'- and 3'-untranslated regions were 74% and 63% identical. The amino acid sequences of the shorter and longer (read through) RNA replicase components, movement protein (MP) and coat protein (CP) were 58, 58. 60 and 46% identical, respectively. The KGMMV-Y genome sequence was also compared partly to that of another strain of KGMMV, KGMMV-C. The CP sequences of KGMMV-Y and KGMMV-C differed by 20 amino acid residues, suggesting that their relationship is more distant than the relationship between CGMMV-SH and CGMMV-W whose CP sequences are identical. The MPs of KGMMV-Y and KGMMV-C, however, differ only by one amino acid residue, although three amino acid substitutions are present in the MPs between CGMMV-SH and CGMMV-W. Two long stretches, one in the RNA replicase and the other in the MP, were highly conserved in KGMMV and CGMMV.