9E70 | pdb_00009e70

Human XRN1 with Adenosine-3',5'-Bisphosphate (pAp) Bound


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 
    0.227 (Depositor), 0.228 (DCC) 
  • R-Value Work: 
    0.187 (Depositor), 0.187 (DCC) 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

Characterization of exoribonuclease XRN1 as a cancer target and identification of adenosine-3',5'-bisphosphate as a potent enzyme inhibitor.

Lockbaum, G.J.Lynes, M.M.Shen, S.A.Liu, J.Holt, N.Nayak, S.P.Knockenhauer, K.E.Yao, S.Sickmier, E.A.Raman, A.Wu, J.Case, A.Shehaj, L.Buker, S.M.Grigoriu, S.Ribich, S.Blakemore, S.J.Sparling, B.A.Duncan, K.W.Copeland, R.A.Silver, S.J.Boriack-Sjodin, P.A.

(2025) Commun Biol 8: 589-589

  • DOI: https://doi.org/10.1038/s42003-025-08005-y
  • Primary Citation of Related Structures:  
    9E70

  • PubMed Abstract: 

    XRN1 (5'-3' exoribonuclease 1) degrades RNA from the 5' → 3' direction and utilizes both single- and double-stranded RNA as substrates. XRN1 plays a critical role in mRNA turnover as well as regulating the cellular response to viral infection. XRN1 also protects the cell by preventing endogenous double-stranded RNA accumulation. XRN1 was identified as a putative vulnerability in a subset of cancer cell lines through analysis of publicly available CRISPR data. The role of XRN1 was explored using a set of non-small cell lung cancer cell lines with differential predicted XRN1 dependency to validate XRN1 as an oncology target. In predicted sensitive cell lines, XRN1 knockout reduced proliferation, increased apoptosis and activated the pPKR and MDA5 dsRNA sensing pathways. To facilitate drug discovery targeting XRN1, a suite of biochemical and biophysical assays was developed. These assays were used to characterize adenosine-3',5'-bisphosphate (pAp), a non-selective nuclease inhibitor, as a nanomolar inhibitor of XRN1. Additionally, the crystal structure of human XRN1 was solved with pAp bound, demonstrating distinct interactions for the compound in the XRN1 active site. These studies provide a strong foundation for the discovery of potent, selective inhibitors of XRN1 as a novel approach to cancer therapeutics.


  • Organizational Affiliation
    • Accent Therapeutics, Lexington, MA, 02421, USA.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
5'-3' exoribonuclease 1
A, B
661Homo sapiensMutation(s): 0 
Gene Names: XRN1SEP1
EC: 3.1.13
UniProt & NIH Common Fund Data Resources
Find proteins for Q8IZH2 (Homo sapiens)
Explore Q8IZH2 
Go to UniProtKB:  Q8IZH2
PHAROS:  Q8IZH2
GTEx:  ENSG00000114127 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8IZH2
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A3P (Subject of Investigation/LOI)
Query on A3P

Download Ideal Coordinates CCD File 
C [auth A]ADENOSINE-3'-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
WHTCPDAXWFLDIH-KQYNXXCUSA-N
PEG
Query on PEG

Download Ideal Coordinates CCD File 
U [auth A]DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
EDO
Query on EDO

Download Ideal Coordinates CCD File 
F [auth A]
G [auth A]
H [auth A]
I [auth A]
J [auth A]
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A],
M [auth A],
N [auth A],
O [auth A],
P [auth A],
Q [auth A],
R [auth A],
S [auth A],
V [auth B],
W [auth B]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
CL
Query on CL

Download Ideal Coordinates CCD File 
T [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
MG
Query on MG

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free:  0.227 (Depositor), 0.228 (DCC) 
  • R-Value Work:  0.187 (Depositor), 0.187 (DCC) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.91α = 90
b = 63.97β = 90
c = 363.15γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
PHASERphasing
Cootmodel building
Aimlessdata scaling

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Not funded--

Revision History  (Full details and data files)

  • Version 1.0: 2025-04-09
    Type: Initial release
  • Version 1.1: 2025-04-23
    Changes: Database references