Hexitol nucleic acid-containing aptamers are efficient ligands of HIV-1 TAR RNA.
The transactivation responsive element (TAR) plays a crucial role in the transcription of the HIV-1 genome upon specific binding of the viral protein Tat and cellular proteins. We have previously identified a RNA hairpin aptamer forming a stable and specific kissing complex with TAR RNA (Ducongé, F., and Toulmé, J. J. (1999) RNA 5, 1605-1614). We chemically modified this aptamer with hexitol nucleic acid (HNA) residues. We demonstrate that a fully HNA-modified aptamer is a poor ligand but, in contrast, mixmers containing both HNA and unmodified RNA nucleotides display interesting properties. Two HNA-RNA mixmers bind to TAR with an equilibrium dissociation constant in the low-nanomolar range and show a reduced nuclease sensitivity. In addition, they show a moderate dependence on magnesium ions for binding to TAR. These HNA-RNA mixmers are able to inhibit transactivation of transcription in an in vitro assay.
Kolb
Gaëlle
G
INSERM U 386; Université Victor Segalen Bordeaux 2, 146 rue Léo-Saignat, F-33076 Bordeaux Cedex, France.
Reigadas
Sandrine
S
Boiziau
Claudine
C
van Aerschot
Arthur
A
Arzumanov
Andrey
A
Gait
Michael J
MJ
Herdewijn
Piet
P
Toulmé
Jean-Jacques
JJ
D001483:Base Sequence; D001665:Binding Sites; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006598:Hexosediphosphates; D007700:Kinetics; D008024:Ligands; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry*; D013816:Thermodynamics; D014158:Transcription, Genetic
D006598:Hexosediphosphates; D008024:Ligands; D012367:RNA, Viral