2KX8

NMR structure of stem-loop 4 from the human 7SK snRNA in complex with arginine


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Preformed protein-binding motifs in 7SK snRNA: structural and thermodynamic comparisons with retroviral TAR.

Durney, M.A.D'Souza, V.M.

(2010) J Mol Biol 404: 555-567

  • DOI: 10.1016/j.jmb.2010.08.042
  • Primary Citation of Related Structures:  
    2KX8

  • PubMed Abstract: 
  • The 7SK small nuclear RNA is a highly conserved non-coding RNA that regulates transcriptional elongation. 7SK utilizes the HEXIM proteins to sequester the transcription factor P-TEFb by a mechanism similar to that used by retroviral TAR RNA to engage Tat and P-TEFb ...

    The 7SK small nuclear RNA is a highly conserved non-coding RNA that regulates transcriptional elongation. 7SK utilizes the HEXIM proteins to sequester the transcription factor P-TEFb by a mechanism similar to that used by retroviral TAR RNA to engage Tat and P-TEFb. Tat has also recently been shown to bind 7SK directly and recruit P-TEFb to TAR. We report here the solution structures of the free and arginine-bound forms of stem loop 4 of 7SK (7SK-SL4). Comparison of the 7SK-SL4 and TAR structures demonstrates the presence of a common arginine sandwich motif. However, arginine binding to 7SK-SL4 is mechanistically distinct and occurs via docking into a pre-organized pocket resulting in a 1000-fold increased affinity. Furthermore, whereas formation of the binding pocket in TAR requires a critical base-triple, hydrogen-bond formation between the equivalent bases in 7SK-SL4 is not essential and the pocket is stabilized solely by a pseudo base-triple platform. In addition, this theme of preformed protein binding motifs also extends into the pentaloop. The configuration of the loop suggests that 7SK-SL4 is poised to make ternary contacts with P-TEFb and HEXIM or Tat. These key differences between 7SK-SL4 and TAR present an opportunity to understand RNA structural adaptation and have implications for understanding differential interactions with Tat.


    Organizational Affiliation

    Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.



Macromolecules
Find similar nucleic acids by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsLengthOrganismImage
7SKA 42Homo sapiens
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ARG
Query on ARG

Download Ideal Coordinates CCD File 
B [auth A]ARGININE
C6 H15 N4 O2
ODKSFYDXXFIFQN-BYPYZUCNSA-O
 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
ARG PDBBind:  2KX8 Kd: 6310 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the least restraint violations 
  • OLDERADO: 2KX8 Olderado

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-09-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance