9SQC | pdb_00009sqc

NMR structure of AT-rich DNA bound to the minor groove ligand JNII40

  • Classification: DNA
  • Organism(s): synthetic construct
  • Expression System: synthetic construct
  • Mutation(s): No 

  • Deposited: 2025-09-22 Released: 2026-07-08 
  • Deposition Author(s): Garavis, M., Ugedo, C.
  • Funding Organization(s): Spanish Ministry of Science, Innovation, and Universities, European Union (EU)

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 10 
  • Conformers Submitted: 10 
  • Selection Criteria: all calculated structures submitted 

wwPDB Validation 3D Report Full Report

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This is version 1.0 of the entry. See complete history

Literature

Direct amidinium-phosphate interactions guide AT-selective DNA binding by a potent antileishmanial drug.

Nue-Martinez, J.J.Ugedo, C.Lagartera, L.Cumella, J.Dardonville, C.Garavis, M.

(2026) Commun Chem 

  • DOI: https://doi.org/10.1038/s42004-026-02073-9
  • Primary Citation Related Structures: 
    9SQC

  • PubMed Abstract: 

    Neglected tropical diseases caused by kinetoplastid parasites remain a major global health challenge, with current chemotherapies offering limited efficacy and safety. JNII40 is a promising bis(pyridine-2-carboxamidine) ligand with potent antiparasitic activity and selectivity in vivo against Leishmania parasites. The compound specifically targets AT-rich regions of DNA, predominant in the mitochondrion of these parasites. We used NMR spectroscopy to determine the high-resolution structure of a DNA duplex containing four consecutive AT repeats in complex with JNII40. The structure reveals that JNII40 binds deeply into the DNA minor groove through a network of direct and water-mediated hydrogen bonds, including direct interactions between amidine protons and DNA phosphate oxygens. These contacts, supported by extensive intermolecular NOEs, explain the high affinity and sequence selectivity toward AT-rich regions observed by calorimetry and NMR. Restrained molecular dynamics simulations highlight the critical role of two ordered water molecules that bridge the ligand and DNA, preserving the geometry of the complex. Ligand insertion induces a noticeable narrowing of the minor groove. Altogether, these findings provide a structural framework for the rational drug design of selective DNA-targeting molecules against kinetoplastid parasites such as Leishmania.


  • Organizational Affiliation
    • Instituto de Química Médica (IQM-CSIC) C/ Juan de la Cierva 3, Madrid, Spain.

Macromolecule Content 

  • Total Structure Weight: 6.52 kDa 
  • Atom Count: 439 
  • Modeled Residue Count: 20 
  • Deposited Residue Count: 20 
  • Unique nucleic acid chains: 1

Macromolecules

Find similar nucleic acids by:  Sequence
Entity ID: 1
MoleculeChains LengthOrganismImage
DNA (5'-D(*CP*AP*TP*AP*TP*AP*TP*AP*TP*G)-3')
A, B
10synthetic construct
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1JPP
(Subject of Investigation/LOI)

Query on A1JPP



Download:Ideal Coordinates CCD File
C [auth B]4-[(~{C}-pyridin-2-ylcarbonimidoyl)amino]-~{N}-[4-[(~{C}-pyridin-2-ylcarbonimidoyl)amino]phenyl]benzamide
C25 H21 N7 O
ZUYUSBWVNHNMIG-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 10 
  • Conformers Submitted: 10 
  • Selection Criteria: all calculated structures submitted 

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Spanish Ministry of Science, Innovation, and UniversitiesSpainRYC2023-043599-I
Spanish Ministry of Science, Innovation, and UniversitiesSpainPID2023-146366NB-I00
Spanish Ministry of Science, Innovation, and UniversitiesSpainMCIN/AEI/10.13039/501100011033
European Union (EU)European UnionPID2022-136438OB-I00
European Union (EU)European UnionPDC2022-133269-I00

Revision History  (Full details and data files)

  • Version 1.0: 2026-07-08
    Type: Initial release