Role of the 5' leader sequence of alfalfa mosaic virus RNA 3 in replication and translation of the viral RNA.
RNA 3 of alfalfa mosaic virus (AIMV) encodes the movement protein P3 and the viral coat protein which is translated from the subgenomic RNA 4. The 5'-leader sequences of RNA 3 of AIMV strains S, A, and Y differ in length from 314 to 392 nucleotides and contain a variable number of internal control regions of type 2 (ICR2 motifs) each located in a 27 nt repeat. Infectious cDNA clones were used to exchange the leader sequences of the three strains. This revealed that the leader sequence controls the specific ratio in which RNAs 3 and 4 are synthesized for each strain. In addition, it specifies strain specific differences in the kinetics of P3 accumulation in plants. Subsequent deletion analysis revealed that a 5'-sequence of 112 nt containing one ICR2 motif was sufficient for a 10 to 20% level of RNA 3 accumulation in protoplasts and a delayed accumulation in plants. An additional leader sequence of maximally 114 nt, containing two ICR2 motifs, was required to permit wildtype levels of RNA 3 accumulation. The effect of deletions in the leader sequence on P3 synthesis in vitro and in vivo was investigated.
van der Vossen
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EA
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, The Netherlands.
Neeleman
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L
Bol
J F
JF
D001483:Base Sequence; D016384:Consensus Sequence; D006860:Hydrogen Bonding; D066298:In Vitro Techniques; D000455:Medicago sativa; D009029:Mosaic Viruses / Q000235:genetics*; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014779:Virus Replication
D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D012367:RNA, Viral