A docking and modelling strategy for peptide-RNA complexes: applications to BIV Tat-TAR and HIV Rev-RBE

In spite of the great interest in the interaction between RNAs and proteins, no general protocol for modelling these complexes is presently available. This methodological vacuum is particularly acute because the structure of few such complexes is known.

A general strategy for docking and modelling RNA-protein complexes has been developed. The docking procedure involves minimizing electrostatic and van der Waals' interaction energies of conformationally rigid structures during docking. After docking, libraries of amino acid sidechain conformations are searched to obtain the best interactions between the peptide and the RNA. Using this method, we have reproduced the structure of a bovine immunodeficiency virus (BIV) Tat peptide bound to BIV TAR RNA and have developed a model for the structure of the arginine-rich HIV-1 Rev peptide (Rev34-50) interacting with the Rev-binding element (RBE).

The resulting model of the Rev34-50-RBE complex predicts that although no single arginine sidechain is responsible for complex formation, residues Arg2, Arg5 and Arg11 are more important for binding than the other arginine residues in the peptide. One model is supported by binding measurements performed on wild-type and mutant RBE molecules with the peptide.