1AKX

HIV-2 TRANS ACTIVATING REGION RNA COMPLEX WITH ARGININAMIDE, NMR, MINIMIZED AVERAGE STRUCTURE

Summary for 1AKX

• Entry DOI: 10.2210/pdb1akx/pdb
• Related: 1AJU
• Descriptor: TAR RNA, ARGININE (2 entities in total)
• Functional Keywords: transcriptional activation, complex (rna-ligand), protein-rna interactions, rna
• Total number of polymer chains: 1
• Total formula weight: 9827.97

Authors

Brodsky, A.S.,Williamson, J.R. (deposition date: 1997-05-27, release date: 1997-11-19, Last modification date: 2024-05-22)

Primary citation

Brodsky, A.S.,Williamson, J.R.
Solution structure of the HIV-2 TAR-argininamide complex.
J.Mol.Biol., 267:624-639, 1997

PubMed Abstract: The trans-activating region (TAR) RNA-Tat protein interaction is important for activation of transciption in the human immunodeficiency virus (HIV). A model complex for this interaction composed of the two base bulge HIV-2 TAR and the amide derivative of arginine was studied by multidimensional heteronuclear NMR. Because of the improved spectral properties of the HIV-2 TAR complex, a larger number of NOEs in the bulge region were observed than in earlier studies of the HIV-1 TAR-argininamide complex. A total of 681 NOE distance restraints were collected and used to determine the solution structure of the HIV-2 TAR-argininamide complex. As observed in the previously proposed model from this lab, the two A-form stems co-axially stack and the critical U23 and the argininamide are located in the major groove. Model calculations including non-experimental restraints indicate that U23 is within hydrogen bonding distance to A27 consistent with the formation of a U x A x U base-triple. Base-triple formation helps open the major groove to increase the accessibility of G26 to hydrogen bond donors from the guanidinium group of argininamide. Argininamide binding is stabilized by stacking of the guanidinium group between the bases of A22 and U23, forming an argininamide sandwich.

PubMed: 9126842
DOI: 10.1006/jmbi.1996.0879

Experimental method

SOLUTION NMR