Identification of a ribosomal frameshift in Leishmania RNA virus 1-4.
Double-stranded Leishmania RNA virus 1-4 (LRV 1-4) has at least four open reading frames (ORFs). The two small ORFs located near its 5' terminus, ORF1 and ORFx, could encode 34- and 60-amino acid polypeptides, respectively. ORF2 encodes an 82-kDa major capsid protein, and ORF3 encodes a 98-kDa polypeptide which contains the consensus sequence for RNA-dependent RNA polymerases of plus-strand and double-stranded RNA viruses. The complete sequence of LRV 1-4 shows that ORF2 and ORF3 overlap by 71 nucleotides, and that ORF3 lacks a potential translation initiation site, suggesting that the viral polymerase may be synthesized as a 180-kDa fusion protein with the virus capsid. In this report, we present evidence for the synthesis of a fusion protein through a ribosomal frameshift. In vitro-translation experiments and immunostudies involving antiserum against the viral capsid protein demonstrated that the overlapping 71 nucleotides of ORF2 and ORF3 are contained in a region which promotes translational frameshifting. Computer analysis of the putative frameshift region revealed a potential pseudoknot structure located within the overlapping 71 nucleotide sequence.
Lee
S E
SE
Department of Biology, Yonsei University, Seoul, Korea.
Suh
J M
JM
Scheffter
S
S
Patterson
J L
JL
Chung
I K
IK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002213:Capsid / Q000235:genetics; D018965:Frameshifting, Ribosomal; D007891:Leishmania / Q000821:virology*; D019199:Leishmaniavirus / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames / Q000235:genetics; D011498:Protein Precursors / Q000235:genetics; D012330:RNA, Double-Stranded / Q000737:chemistry; D012367:RNA, Viral / Q000737:chemistry; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics
D011498:Protein Precursors; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase