7SQL | pdb_00007sql

Crystal structure of human uridine-cytidine kinase 2 complexed with a weak small molecule inhibitor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 
    0.257 (Depositor), 0.257 (DCC) 
  • R-Value Work: 
    0.200 (Depositor), 0.204 (DCC) 
  • R-Value Observed: 
    0.203 (Depositor) 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history

Literature

Structure-Based Prototyping of Allosteric Inhibitors of Human Uridine/Cytidine Kinase 2 (UCK2).

Mashayekh, S.Stunkard, L.M.Kienle, M.Mathews, I.I.Khosla, C.

(2022) Biochemistry 61: 2261-2266

  • DOI: https://doi.org/10.1021/acs.biochem.2c00451
  • Primary Citation Related Structures: 
    7SQL

  • PubMed Abstract: 

    Pyrimidine nucleotide biosynthesis in humans is a promising chemotherapeutic target for infectious diseases caused by RNA viruses. Because mammalian cells derive pyrimidine ribonucleotides through a combination of de novo biosynthesis and salvage, combined inhibition of dihydroorotate dehydrogenase (DHODH; the first committed step in de novo pyrimidine nucleotide biosynthesis) and uridine/cytidine kinase 2 (UCK2; the first step in salvage of exogenous nucleosides) strongly attenuates viral replication in infected cells. However, while several pharmacologically promising inhibitors of human DHODH are known, to date there are no reports of medicinally viable leads against UCK2. Here, we use structure-based drug prototyping to identify two classes of promising leads that noncompetitively inhibit UCK2 activity. In the process, we have identified a hitherto unknown allosteric site at the intersubunit interface of this homotetrameric enzyme. By reducing the k cat of human UCK2 without altering its K M , these new inhibitors have the potential to enable systematic dialing of the fractional inhibition of pyrimidine salvage to achieve the desired antiviral effect with minimal host toxicity.


  • Organizational Affiliation
    • Department of Chemistry, Stanford University, Stanford, California 94305, United States.

Macromolecule Content 

  • Total Structure Weight: 114.76 kDa 
  • Atom Count: 7,321 
  • Modeled Residue Count: 849 
  • Deposited Residue Count: 1,000 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Uridine-cytidine kinase 2
A, B, C, D
250Homo sapiensMutation(s): 0 
Gene Names: UCK2UMPK
EC: 2.7.1.48
UniProt & NIH Common Fund Data Resources
Find proteins for Q9BZX2 (Homo sapiens)
Explore Q9BZX2 
Go to UniProtKB:  Q9BZX2
PHAROS:  Q9BZX2
GTEx:  ENSG00000143179 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9BZX2
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
AQX
(Subject of Investigation/LOI)

Query on AQX



Download:Ideal Coordinates CCD File
K [auth C],
N [auth D]
N-(4-bromophenyl)-2-{[1-(4-fluorophenyl)-4-oxo-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6-yl]sulfanyl}acetamide
C19 H13 Br F N5 O2 S
VCFXXKDAPCCCGQ-UHFFFAOYSA-N
PG4

Query on PG4



Download:Ideal Coordinates CCD File
H [auth B],
O [auth D]
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
PGE

Query on PGE



Download:Ideal Coordinates CCD File
E [auth A],
F [auth A]
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
PEG

Query on PEG



Download:Ideal Coordinates CCD File
I [auth B],
L [auth C],
Q [auth D]
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
GOL

Query on GOL



Download:Ideal Coordinates CCD File
G [auth A],
J [auth B],
M [auth C],
P [auth D]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free:  0.257 (Depositor), 0.257 (DCC) 
  • R-Value Work:  0.200 (Depositor), 0.204 (DCC) 
  • R-Value Observed: 0.203 (Depositor) 
Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.087α = 90
b = 93.893β = 90
c = 157.497γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Other privatePTA 1256351-1-GAMDE

Revision History  (Full details and data files)

  • Version 1.0: 2022-10-12
    Type: Initial release
  • Version 1.1: 2023-04-26
    Changes: Database references
  • Version 1.2: 2023-10-25
    Changes: Data collection, Refinement description