MOLECULAR-CLONING AND SEQUENCING OF THE 3'-TERMINAL REGION OF CYMBIDIUM-MOSAIC-VIRUS GENOMIC RNA AND STRUCTURAL-ANALYSIS OF THE 3'-NONCODING REGION

A Korean isolate of the cymbidium mosaic virus (CymMV), denoted CymMV- K, was originally isolated from a naturally infected Dendrobium 'Sprin g Night', Reverse transcription-polymerase chain reaction and conventi onal cDNA synthesis methods were applied to clone the 3'-terminal regi on of the viral RNA, The determined sequence contained a full length o pen reading frame coding for the viral coat protein and 3'-noncoding r egion, The amino acid sequence homology between CymMV-K and the Singap ore isolate of CymMV was 94.1% with 13 amino acid substitutions, The 3 '-noncoding region (NCR) of CymMV-K RNA contained three distinctive mo tifs (I, II, and III) conserved among potexviruses, One pseudoknot str ucture was present at the 3'-proximal part of the 3'-NCR when secondar y and three-dimensional folding structures were predicted.