title: A retroviral RNA secondary structure required for efficient initiation of reverse transcription.
abstract: Genetic evidence is presented which suggests the existence of an important structural element in the 5' noncoding region of avian retrovirus RNA. The proposed structure, which we term the U5-leader stem, is composed of sequences in the middle of U5 and in the leader, flanking the primer-binding site. U5 and leader mutations which would disrupt this structure caused a partial replication defect. However, nucleotide substitutions in the leader, which would structurally compensate for a U5 deletion mutation, restored normal replication. Analysis of replication intermediates of viruses with the above mutations suggests that the U5-leader stem is required for efficient DNA synthesis in vivo and for initiation of DNA synthesis from the tRNA(Trp) primer in melittin-activated virions. However, this structure does not appear to be required for binding of the tRNA(Trp) primer to viral RNA. These results support a role for the U5-leader stem structure, independent of its primary sequence, in the initiation of retroviral replication.
authors: Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106.
authors: D
authors: D
authors: Cobrinik
authors: L
authors: L
authors: Soskey
authors: J
authors: J
authors: Leis
mesh_terms: D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D008555:Melitten; D008838:Microcomputers; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000235:genetics*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D012190:Retroviridae / Q000235:genetics* / Q000502:physiology; D012984:Software; D014162:Transfection; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral; D008555:Melitten; D012194:RNA-Directed DNA Polymerase