3IKI | pdb_00003iki

5-SMe-dU containing DNA octamer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.38 Å
  • R-Value Free: 
    0.194 (Depositor), 0.202 (DCC) 
  • R-Value Work: 
    0.178 (Depositor), 0.184 (DCC) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

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This is version 1.4 of the entry. See complete history

Literature

Hydrogen bond formation between the naturally modified nucleobase and phosphate backbone.

Sheng, J.Zhang, W.Hassan, A.E.Gan, J.Soares, A.S.Geng, S.Ren, Y.Huang, Z.

(2012) Nucleic Acids Res 40: 8111-8118

  • DOI: https://doi.org/10.1093/nar/gks426
  • Primary Citation Related Structures: 
    3IKI, 3LTR

  • PubMed Abstract: 

    Natural RNAs, especially tRNAs, are extensively modified to tailor structure and function diversities. Uracil is the most modified nucleobase among all natural nucleobases. Interestingly, >76% of uracil modifications are located on its 5-position. We have investigated the natural 5-methoxy (5-O-CH(3)) modification of uracil in the context of A-form oligonucleotide duplex. Our X-ray crystal structure indicates first a H-bond formation between the uracil 5-O-CH(3) and its 5'-phosphate. This novel H-bond is not observed when the oxygen of 5-O-CH(3) is replaced with a larger atom (selenium or sulfur). The 5-O-CH(3) modification does not cause significant structure and stability alterations. Moreover, our computational study is consistent with the experimental observation. The investigation on the uracil 5-position demonstrates the importance of this RNA modification at the atomic level. Our finding suggests a general interaction between the nucleobase and backbone and reveals a plausible function of the tRNA 5-O-CH(3) modification, which might potentially rigidify the local conformation and facilitates translation.


  • Organizational Affiliation
    • Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA.

Macromolecule Content 

  • Total Structure Weight: 2.56 kDa 
  • Atom Count: 202 
  • Modeled Residue Count: 8 
  • Deposited Residue Count: 8 
  • Unique nucleic acid chains: 1

Macromolecules

Find similar nucleic acids by:  Sequence
Entity ID: 1
MoleculeChains LengthOrganismImage
5'-D(*GP*(UMS)P*GP*(US2)P*AP*CP*AP*C)-3'8N/A
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
MG

Query on MG



Download:Ideal Coordinates CCD File
B [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.38 Å
  • R-Value Free:  0.194 (Depositor), 0.202 (DCC) 
  • R-Value Work:  0.178 (Depositor), 0.184 (DCC) 
Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.882α = 90
b = 42.882β = 90
c = 23.687γ = 90
Software Package:
Software NamePurpose
CBASSdata collection
PHASESphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-03-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2012-06-13
    Changes: Database references
  • Version 1.3: 2012-09-26
    Changes: Database references
  • Version 1.4: 2023-09-06
    Changes: Data collection, Database references, Derived calculations, Refinement description