Binding and dissociation of human topoisomerase I with hairpin-loop RNAs: implications for the regulation of HIV-1 replication.
Cellular topoisomerase I has been reported to be present in retroviral particles and to enhance viral cDNA synthesis; however, the mechanisms involved remain unknown. In the present study, it has been demonstrated that human topoisomerase I combines with a stem-loop RNA and that the bound topoisomerase I can be dissociated from RNA substrates in the presence of ATP. In addition, in vitro cleaved synthetic RNA bound by topoisomerase I is subsequently relegated when the topoisomerase I is dissociated by ATP. A mechanism is proposed in which human topoisomerase I is carried into virions and regulates the repair of genomic RNA by its ligation activity.
Takahashi
Hidehiro
H
Department of Pathology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan. htakahas@nih.go.jp
Sawa
Hirofumi
H
Hasegawa
Hideki
H
Sata
Tetsutaro
T
Hall
William
W
Kurata
Takeshi
T
D000255:Adenosine Triphosphate / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers; D004261:DNA Replication; D004264:DNA Topoisomerases, Type I / Q000737:chemistry* / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014158:Transcription, Genetic; D014771:Virion / Q000201:enzymology / Q000235:genetics; D014779:Virus Replication / Q000502:physiology*
D017931:DNA Primers; D012367:RNA, Viral; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D004264:DNA Topoisomerases, Type I