Cooperative dimerization of a stably folded protein directed by a flexible RNA in the assembly of the HIV Rev dimer–RRE stem II complex. Issue 5 (1st December 2015)

• Record Type: Journal Article
• Authors: Tanamura, Satoshi; Terakado, Hiroto; Harada, Kazuo
• Is Part Of: Journal of molecular recognition. Volume 29:Issue 5(2016)
• Page Start: 199
• Page End: 209
• Publication Date: 2015-12-01
• Subjects: HIV Rev‐RRE complex -- RNA‐protein interactions -- RNA structure -- protein folding -- cooperativity; Molecular recognition -- Periodicals; Models, Molecular -- Periodicals; Molecular Conformation -- Periodicals; Molecular Sequence Data -- Periodicals; Molecular Structure -- Periodicals; Carrier Proteins -- Periodicals; 572.8
• DOI: 10.1002/jmr.2518
• Languages: English
• ISSNs: 0952-3499

Abstract

Abstract : The binding of the HIV‐1 Rev protein as an oligomer to a viral RNA element, the Rev‐response element (RRE), mediates nuclear export of genomic RNA. Assembly of the Rev–RRE ribonucleoprotein (RNP) complex is nucleated by the binding of the first Rev molecule to stem IIB of the RRE. This is followed by stepwise addition of a total of ~six Rev molecules along the RRE through a combination of RNA–protein and protein–protein interactions. RRE stem II, which forms a three‐way junction consisting of stems IIA, IIB and IIC, has been shown to bind to two Rev molecules in a cooperative manner, with the second Rev molecule binding to the junction region of stem II. The results of base substitutions at the stem II junction, and characterization of stem II junction variants selected from a randomized library showed that an "open" flexible structure is preferred for binding of the second Rev molecule, and that binding of the second Rev molecule to the junction region is not sequence‐specific. Alanine substitutions of a number of Rev amino acid residues implicated to be important for Rev folding in previous structural studies were found to result in a dramatic decrease in the binding of the second Rev molecule. These results support the model that proper folding of Rev is critical in ensuring that the flexible RRE is able to correctly position Rev molecules for specific RNP assembly, and suggests that targeting Rev folding may be effective in the inhibition of Rev function. Copyright © 2015 John Wiley & Sons, Ltd. Abstract : Assembly of the HIV Rev–Rev‐response element (RRE) ribonucleoprotein complex is nucleated by the binding of the first Rev molecule to stem IIB of the RRE, which is followed by binding of the second Rev molecule to an adjacent RNA junction region. We find that an "open" flexible RNA junction region is preferred for binding of a stably folded Rev molecule for formation of the ternary complex. The results suggest that targeting Rev folding may be effective in the inhibition of Rev function.