8AYG | pdb_00008ayg

Crystal structure of an intramolecular i-motif at the insulin-linked polymorphic region (ILPR)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 
    0.295 (Depositor), 0.290 (DCC) 
  • R-Value Work: 
    0.249 (Depositor), 0.240 (DCC) 
  • R-Value Observed: 
    0.251 (Depositor) 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural insights into i-motif DNA structures in sequences from the insulin-linked polymorphic region.

Guneri, D.Alexandrou, E.El Omari, K.Dvorakova, Z.Chikhale, R.V.Pike, D.T.S.Waudby, C.A.Morris, C.J.Haider, S.Parkinson, G.N.Waller, Z.A.E.

(2024) Nat Commun 15: 7119-7119

  • DOI: https://doi.org/10.1038/s41467-024-50553-0
  • Primary Citation of Related Structures:  
    8AYG

  • PubMed Abstract: 

    The insulin-linked polymorphic region is a variable number of tandem repeats region of DNA in the promoter of the insulin gene that regulates transcription of insulin. This region is known to form the alternative DNA structures, i-motifs and G-quadruplexes. Individuals have different sequence variants of tandem repeats and although previous work investigated the effects of some variants on G-quadruplex formation, there is not a clear picture of the relationship between the sequence diversity, the DNA structures formed, and the functional effects on insulin gene expression. Here we show that different sequence variants of the insulin linked polymorphic region form different DNA structures in vitro. Additionally, reporter genes in cellulo indicate that insulin expression may change depending on which DNA structures form. We report the crystal structure and dynamics of an intramolecular i-motif, which reveal sequences within the loop regions forming additional stabilising interactions that are critical to formation of stable i-motif structures. The outcomes of this work reveal the detail in formation of stable i-motif DNA structures, with potential for rational based drug design for compounds to target i-motif DNA.


  • Organizational Affiliation
    • School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK.

Macromolecules
Find similar nucleic acids by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains LengthOrganismImage
Insulin-linked polymorphic region, ILPR DNA (31-MER)
A, B
31Homo sapiens
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free:  0.295 (Depositor), 0.290 (DCC) 
  • R-Value Work:  0.249 (Depositor), 0.240 (DCC) 
  • R-Value Observed: 0.251 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.415α = 90
b = 51.513β = 90
c = 69.847γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
SHELXphasing
PDB_EXTRACTdata extraction
xia2.multiplexdata reduction

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Other privateUnited Kingdomgrand code: 565921, award:177365

Revision History  (Full details and data files)

  • Version 1.0: 2023-09-13
    Type: Initial release
  • Version 1.1: 2024-09-11
    Changes: Database references