An Arg/Lys-rich core peptide mimics TRBP binding to the HIV-1 TAR RNA upper-stem/loop
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- 作者：Erard ; Monique ; Barker ; David G. ; Amalric ; Franç ; ois ; Jeang ; Kuan-Teh ; Gatignol ; Anne
- 关键词：TAR ; TRBP ; double-stranded RNA-binding domain ; protein-RNA interaction ; molecular modelling ; HIV-1 ; human immunodeficiency virus type-1 ; LTR ; long terminal repeat ; TAR ; trans-activation responsive ; TRBP ; TAR RNA binding protein ; PKR ; protein kinase dsRNA-
- 刊名：Journal of Molecular Biology
- 出版年：1998
- 出版时间：June 26, 1998
- 年：1998
- 卷：279
- 期：5
- 页码：1085-1099
- 全文大小：952 K
文摘
TRBP is a cellular protein that binds to the HIV-1 leader RNA, TAR. Circular dichroism experiments have shown that a 24 amino acid peptide (TR1), located within a dsRNA binding domain (dsRBD) of TRBP, binds TAR with a 3:1 stoichiometry, eliciting a conformational change involving base unstacking. The binding characteristics of synthetic structural variants of TAR indicate that guanine residues play a key role in the TR1-RNA interaction and that binding sites exist in the upper-stem/loop and lower stem region of TAR. Deletion analysis of TR1 has led to the identification of a 15 amino acid subpeptide (TR13) which is necessary and sufficient to bind to the high affinity upper-stem/loop binding site of TAR. Alanine scanning of TR13 has revealed that mutations in either Lys or Arg residues result in altered TAR-binding, and molecular modelling/docking experiments have shown that the two Arg residues of TR13 can interact with two appropriately spaced guanine residues in the upper-stem/loop of TAR. The TR13 lysine residues appear to be essential for maintaining structural integrity and the correct positioning of the Arg side-chains. We propose that TRBP binds TAR by means of a “2-G hook” motif and that the binding specificity of this particular member of the family of double-stranded RNA-binding proteins lies within the highly conserved dsRBD core motif. Finally, our results also suggest that TRBP may function in vivo by modifying the tertiary structure of TAR RNA.