How the HIV-1 Nucleocapsid Protein Binds and Destabilises the (-)Primer Binding Site During Reverse Transcription.
Fiche publication
Date publication
novembre 2008
Auteurs
Membres identifiés du Cancéropôle Est :
Pr MELY Yves
Tous les auteurs :
Bourbigot S, Ramalanjaona N, Boudier C, Salgado GFJ, Roques BP, Mely Y, Bouaziz S, Morellet N
Lien Pubmed
Résumé
The human immunodeficiency virus type 1 nucleocapsid protein (NCp7) plays an important role in the second strand transfer during reverse transcription. It promotes annealing of the 18-nucleotide complementary DNA primer-binding site (PBS) sequences at the 3' ends of (-)DNA and (+) DNA. NMR studies show that NCp7(12-55) and NCp7(1-55) interact at the 5' end of the loop of Delta/P(-)PBS, a (-)PBS derivative without the 3' protruding sequence, in a slow-exchange equilibrium. This interaction is mediated through the binding of the hydrophobic plateau (Val13, Phe16, Thr24, Ala25, Trp37, and Met46) on the zinc finger domain of both peptides to the 5-CTG-7 sequence of Delta P(-)PBS. The stacking of the Trp37 aromatic ring with the G7 residue likely constitutes the determinant factor of the interaction. Although NCp7(12-55) does not melt the Delta P(-)PBS stem-loop structure, it opens the loop and weakens the C5-G11 base pair next to the loop. Moreover, NCp7(12-55) was also found to bind but with lower affinity to the 10-CGG-12 sequence in an intermediate-exchange equilibrium on the NMR time scale. The loop modifications may favour a kissing interaction with the complementary (+)PBS loop. Moreover, the weakening of the upper base pair of the stem likely promotes the melting of the stem that is required to convert the kissing complex into the final (+/-)PBS extended duplex. (c) 2008 Elsevier Ltd. All rights reserved.
Référence
J Mol Biol. 2008 Nov 28;383(5):1112-28