Binding of a cyclic BIV beta-Tat peptide with its TAR RNA construct

The ability of RNA structures to adopt diverse yet complex tertiary structu res has resulted in numerous fascinating RNA-protein recognition events. It was recently reported that a close relative of the HIV Rev peptide, namely a 17 residue Tat peptide from bovine immune-deficiency virus (BIV), is abl e to bind to the 28 nucleotide BIV TAR RNA construct. Here we report that b y simply converting the 17 residue beta -ribbon peptide structure to a 19 r esidue cyclopeptide, the binding affinity (K-d) Of the resulting cyclopepti de to the TAR RNA target, observed by fluorescence binding study, was enhan ced approximately 5-fold. (C) 2000 Elsevier Science Ltd. All rights reserve d.