Properties of a novel satellite RNA associated with tomato bushy stunt virus infections.
The biological and molecular properties of a novel satellite RNA (satRNA L) associated with tomato bushy stunt virus (TBSV) are described. satRNA L consisted of a linear single-stranded RNA of 615 nt, lacked significant open reading frames (ORFs) and had no sequence identity with the helper genome other than in the 5'-proximal 7 nt and in a central region that is also conserved in all tombusvirus genomic, defective interfering and satellite RNAs. Secondary-structure analysis showed the presence of high-order domains similar to those described for other tombusvirus RNAs. Shorter-than-unit-length molecules were shown not to be related to a silencing mechanism. satRNA L did not modify the symptoms induced by TBSV under any of the temperature conditions tested. A full-length cDNA clone was constructed and used in co-inoculations with transcripts of carnation Italian ringspot virus (CIRV) and cymbidium ringspot virus (CymRSV). CIRV, but not CymRSV, supported the replication of satRNA L. Using CIRV-CymRSV hybrid infectious clones, two regions were identified as possible determinants of the different ability to support satRNA L replication. The first region was in the 5'-untranslated region, which folds differently in CymRSV in comparison with CIRV and TBSV; the second region was in the ORF1-encoded protein where a more efficient satRNA L-binding domain is suggested to be present in CIRV.
Rubino
L
L
Istituto di Virologia Vegetale del CNR, Unità Organizzativa di Bari, Bari, Italy. l.rubino@ba.ivv.cnr.it
Russo
M
M
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D001483:Base Sequence; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010935:Plant Diseases / Q000821:virology*; D019244:RNA, Satellite / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014026:Nicotiana / Q000821:virology; D017864:Tombusvirus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D019244:RNA, Satellite; D012367:RNA, Viral