Structural bases of the annealing of primer tRNA3Lys to the HIV-1 viral RNA

To promote the initiation of reverse transcription, the HIV-1 virus uses a host tRNA as a primer, tRNA(3)(Lys). The annealing of tRNA(3)(Lys) to the viral RNA requires the breaking of the 3D structure of the tRNA and RNA rearrangements, to form a stable initiation complex recognised by the reverse transcriptase. The annealing is mediated by a viral factor, the nucleocapsid protein. This protein has been studied for a long while to define the role of its different sub-domains and their mode of action. Only recently, a consensus view seems to emerge. The structure of the initiation complex, is still discussed. The goal of this review is to clarify what is known about the formation and the structure of the tRNA/viral RNA complex and the role of the nucleocapsid protein from a structural point of view.