5UEE

RNA primer-template complex with guanosine dinucleotide ligand G(5')ppp(5')G


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.234 

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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Insight into the mechanism of nonenzymatic RNA primer extension from the structure of an RNA-GpppG complex.

Zhang, W.Tam, C.P.Walton, T.Fahrenbach, A.C.Birrane, G.Szostak, J.W.

(2017) Proc Natl Acad Sci U S A 114: 7659-7664

  • DOI: https://doi.org/10.1073/pnas.1704006114
  • Primary Citation of Related Structures:  
    5UED, 5UEE, 5UEF, 5UEG

  • PubMed Abstract: 

    The nonenzymatic copying of RNA templates with imidazole-activated nucleotides is a well-studied model for the emergence of RNA self-replication during the origin of life. We have recently discovered that this reaction can proceed through the formation of an imidazolium-bridged dinucleotide intermediate that reacts rapidly with the primer. To gain insight into the relationship between the structure of this intermediate and its reactivity, we cocrystallized an RNA primer-template complex with a close analog of the intermediate, the triphosphate-bridged guanosine dinucleotide GpppG, and solved a high-resolution X-ray structure of the complex. The structure shows that GpppG binds the RNA template through two Watson-Crick base pairs, with the primer 3'-hydroxyl oriented to attack the 5'-phosphate of the adjacent G residue. Thus, the GpppG structure suggests that the bound imidazolium-bridged dinucleotide intermediate would be preorganized to react with the primer by in-line S N 2 substitution. The structures of bound GppG and GppppG suggest that the length and flexibility of the 5'-5' linkage are important for optimal preorganization of the complex, whereas the position of the 5'-phosphate of bound pGpG explains the slow rate of oligonucleotide ligation reactions. Our studies provide a structural interpretation for the observed reactivity of the imidazolium-bridged dinucleotide intermediate in nonenzymatic RNA primer extension.


  • Organizational Affiliation

    Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114.


Macromolecules

Find similar nucleic acids by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains LengthOrganismImage
RNA (5'-R(*(LCC)P*(LCC)P*(LCC)P*GP*AP*CP*UP*UP*AP*AP*GP*UP*CP*G)-3')
A, B
14synthetic construct
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.234 
  • Space Group: P 3 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.964α = 90
b = 46.964β = 90
c = 83.103γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-07-05
    Type: Initial release
  • Version 1.1: 2017-07-19
    Changes: Database references
  • Version 1.2: 2017-08-02
    Changes: Database references
  • Version 1.3: 2023-10-04
    Changes: Data collection, Database references, Derived calculations, Refinement description