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Updated: Jul 11, 2026

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
Published on: December 27, 2016
Conformation of the TAR RNA-arginine complex by NMR spectroscopy
J D Puglisi1, R Tan, B J Calnan
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139.
Abstract:
The messenger RNAs of human immunodeficiency virus-1 (HIV-1) have an RNA hairpin structure, TAR, at their 5' ends that contains a six-nucleotide loop and a three-nucleotide bulge. The conformations of TAR RNA and of TAR with an arginine analog specifically bound at the binding site for the viral protein, Tat, were characterized by nuclear magnetic resonance (NMR) spectroscopy. Upon arginine binding, the bulge changes conformation, and essential nucleotides for binding, U23 and A27.U38, form a base-triple interaction that stabilizes arginine hydrogen bonding to G26 and phosphates. Specificity in the arginine-TAR interaction appears to be derived largely from the structure of the RNA.
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