Sequences involved in the dimerisation of human T cell leukaemia virus type-1 RNA.
The formation of a genomic RNA dimer appears to be a critical step in the life cycle of all retroviruses. To investigate the site and nucleotide interactions involved in this process, a 531 bp DNA fragment encompassing sequences up- and downstream of the splice donor in human T cell leukaemia virus type 1 (HTLV-1) was inserted into a plasmid vector under the control of the SP6 promoter. RNA transcripts generated in vitro from this template formed dimers which could be dissociated by heating at 60-80 degrees C for 3 min. The physical properties of the dimeric RNA were not consistent with either Watson-Crick base pairing or guanine tetrad formation as being solely responsible for the interaction. Deletion mutagenesis identified a 32 nt sequence required for dimerisation. Computer modelling was carried out in order to identify putative RNA secondary structures within this essential region. A stem-loop structure was identified, the stem of which was conserved among different sequenced isolates of HTLV-1. This sequence also contains a 15 nt palindrome. We sought by disruptive and compensatory mutagenesis to define the possible roles of these two structures in dimer linkage.
Greatorex
J S
JS
Department of Medicine, University of Cambridge, UK.
Laisse
V
V
Dockhelar
M C
MC
Lever
A M
AM
D001483:Base Sequence; D003198:Computer Simulation; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics; D017384:Sequence Deletion; D013329:Structure-Activity Relationship
D012333:RNA, Messenger; D012367:RNA, Viral