RNA and N3 -> P5 ' kissing aptamers targeted to the trans-activation responsive (TAR) RNA of the human immunodeficiency virus-1

We used in vitro selection to identify RNA aptamers able to selectively bin d to the TAR RNA motif of HIV-1, an unperfect RNA hairpin involved in the t ranscription of the retroviral genome. We selected aptameric RNA hairpins g iving rise to kissing complexes with TAR. The N3' --> P5' phosphoramidate v ariant of the aptamer bind to TAR with a Kd in the low nanomolar range. How ever, only the RNA-RNA loop-loop complex is recognized by the Rop protein o f E. coli which is specific for kissing complexes.