2KY0

The Structure of RNA Internal Loops with Tandem AG Pairs: 5'GAGC/3'CGAG


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 40 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

RNA internal loops with tandem AG pairs: the structure of the 5'GAGU/3'UGAG loop can be dramatically different from others, including 5'AAGU/3'UGAA.

Hammond, N.B.Tolbert, B.S.Kierzek, R.Turner, D.H.Kennedy, S.D.

(2010) Biochemistry 49: 5817-5827

  • DOI: https://doi.org/10.1021/bi100332r
  • Primary Citation of Related Structures:  
    2KXZ, 2KY0, 2KY1, 2KY2

  • PubMed Abstract: 

    Thermodynamic stabilities of 2 x 2 nucleotide tandem AG internal loops in RNA range from -1.3 to +3.4 kcal/mol at 37 degrees C and are not predicted well with a hydrogen-bonding model. To provide structural information to facilitate development of more sophisticated models for the sequence dependence of stability, we report the NMR solution structures of five RNA duplexes: (rGACGAGCGUCA)(2), (rGACUAGAGUCA)(2), (rGACAAGUGUCA)(2), (rGGUAGGCCA)(2), and (rGACGAGUGUCA)(2). The structures of these duplexes are compared to that of the previously solved (rGGCAGGCC)(2) (Wu, M., SantaLucia, J., Jr., and Turner, D. H. (1997) Biochemistry 36, 4449-4460). For loops bounded by Watson-Crick pairs, the AG and Watson-Crick pairs are all head-to-head imino-paired (cis Watson-Crick/Watson-Crick). The structures suggest that the sequence-dependent stability may reflect non-hydrogen-bonding interactions. Of the two loops bounded by G-U pairs, only the 5'UAGG/3'GGAU loop adopts canonical UG wobble pairing (cis Watson-Crick/Watson-Crick), with AG pairs that are only weakly imino-paired. Strikingly, the 5'GAGU/3'UGAG loop has two distinct duplex conformations, the major of which has both guanosine residues (G4 and G6 in (rGACGAGUGUCA)(2)) in a syn glycosidic bond conformation and forming a sheared GG pair (G4-G6*, GG trans Watson-Crick/Hoogsteen), both uracils (U7 and U7*) flipped out of the helix, and an AA pair (A5-A5*) in a dynamic or stacked conformation. These structures provide benchmarks for computational investigations into interactions responsible for the unexpected differences in loop free energies and structure.


  • Organizational Affiliation

    Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, USA.


Macromolecules

Find similar nucleic acids by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains LengthOrganismImage
5'-R(*GP*AP*CP*GP*AP*GP*CP*GP*UP*CP*A)-3'
A, B
11N/A
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 40 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-06-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2022-03-16
    Changes: Data collection, Database references, Derived calculations