Mutations in a satellite RNA of turnip crinkle virus result in addition of poly(U) in vivo.
Turnip crinkle virus (TCV) is associated with many subviral RNAs including satellite (sat-) RNAs which require a helper virus for infectivity. When plants were inoculated with TCV and transcripts of TCV sat-RNA C containing deletions of 3 to 8 nucleotides beginning at position 100 and extending toward the 5' end, some of the sat-RNA isolated from plants migrated more slowly than expected on denaturing polyacrylamide gels. Cleavage of the sat-RNA into two segments by digestion with RNase H following hybridization to an oligonucleotide complementary to internal sat-RNA sequence indicated that the 5' one-third of the molecule was involved in the abnormal gel migration. Sat-RNAs derived from transcripts with a deletion of bases in position 96-100 were cloned. Sequencing of the cDNAs revealed that the aberrant migration of the sat-RNAs was due to the presence of variable lengths of poly(U) 10 nucleotides downstream from the deletion at a position which already contained five U residues. Deletions extending toward the 3' end in the same region did not result in poly(U) additions. Mutations in the original five U residues along with the 5' deletions also did not lead to poly(U) additions. The insertion of poly(U) in TCV sat-RNA C may be a new example of replicase stuttering with the distinction that it only occurs following specific upstream mutations.
Carpenter
C D
CD
Department of Biochemistry, University of Massachusetts, Amherst 01003.
Cascone
P J
PJ
Simon
A E
AE
D001483:Base Sequence; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010942:Plant Viruses / Q000235:genetics*; D011072:Poly U / Q000378:metabolism*; D012313:RNA / Q000235:genetics* / Q000378:metabolism; D012328:RNA Viruses / Q000235:genetics*; D019244:RNA, Satellite; D012367:RNA, Viral
D019244:RNA, Satellite; D012367:RNA, Viral; D011072:Poly U; D012313:RNA