6QYQ

Crystal structure of human thymidylate synthase (hTS) variant R175C


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.187 

Starting Model: experimental
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Ligand Structure Quality Assessment 


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Literature

Structural and Functional Characterization of the Human Thymidylate Synthase (hTS) Interface Variant R175C, New Perspectives for the Development of hTS Inhibitors.

Pozzi, C.Ferrari, S.Luciani, R.Costi, M.P.Mangani, S.

(2019) Molecules 24

  • DOI: https://doi.org/10.3390/molecules24071362
  • Primary Citation of Related Structures:  
    6QYQ

  • PubMed Abstract: 

    Human thymidylate synthase (hTS) is pivotal for cell survival and proliferation, indeed it provides the only synthetic source of dTMP, required for DNA biosynthesis. hTS represents a validated target for anticancer chemotherapy. However, active site-targeting drugs towards hTS have limitations connected to the onset of resistance. Thus, new strategies have to be applied to effectively target hTS without inducing resistance in cancer cells. Here, we report the generation and the functional and structural characterization of a new hTS interface variant in which Arg175 is replaced by a cysteine. Arg175 is located at the interface of the hTS obligate homodimer and protrudes inside the active site of the partner subunit, in which it provides a fundamental contribution for substrate binding. Indeed, the R175C variant results catalytically inactive. The introduction of a cysteine at the dimer interface is functional for development of new hTS inhibitors through innovative strategies, such as the tethering approach. Structural analysis, performed through X-ray crystallography, has revealed that a cofactor derivative is entrapped inside the catalytic cavity of the hTS R175C variant. The peculiar binding mode of the cofactor analogue suggests new clues exploitable for the design of new hTS inhibitors.


  • Organizational Affiliation

    Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2020, University of Siena, via Aldo Moro 2, 53100 Siena, Italy. pozzi4@unisi.it.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Thymidylate synthase325Homo sapiensMutation(s): 1 
Gene Names: TYMSTSOK/SW-cl.29
EC: 2.1.1.45
UniProt & NIH Common Fund Data Resources
Find proteins for P04818 (Homo sapiens)
Explore P04818 
Go to UniProtKB:  P04818
PHAROS:  P04818
GTEx:  ENSG00000176890 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04818
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Thymidylate synthaseB [auth C]325Homo sapiensMutation(s): 1 
Gene Names: TYMSTSOK/SW-cl.29
EC: 2.1.1.45
UniProt & NIH Common Fund Data Resources
Find proteins for P04818 (Homo sapiens)
Explore P04818 
Go to UniProtKB:  P04818
PHAROS:  P04818
GTEx:  ENSG00000176890 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04818
Sequence Annotations
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Thymidylate synthaseC [auth B]325Homo sapiensMutation(s): 1 
Gene Names: TYMSTSOK/SW-cl.29
EC: 2.1.1.45
UniProt & NIH Common Fund Data Resources
Find proteins for P04818 (Homo sapiens)
Explore P04818 
Go to UniProtKB:  P04818
PHAROS:  P04818
GTEx:  ENSG00000176890 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04818
Sequence Annotations
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  • Reference Sequence
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Entity ID: 4
MoleculeChains Sequence LengthOrganismDetailsImage
Thymidylate synthase325Homo sapiensMutation(s): 1 
Gene Names: TYMSTSOK/SW-cl.29
EC: 2.1.1.45
UniProt & NIH Common Fund Data Resources
Find proteins for P04818 (Homo sapiens)
Explore P04818 
Go to UniProtKB:  P04818
PHAROS:  P04818
GTEx:  ENSG00000176890 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04818
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
FFO
Query on FFO

Download Ideal Coordinates CCD File 
M [auth B],
P [auth D]
N-[4-({[(6S)-2-amino-5-formyl-4-oxo-3,4,5,6,7,8-hexahydropteridin-6-yl]methyl}amino)benzoyl]-L-glutamic acid
C20 H23 N7 O7
VVIAGPKUTFNRDU-STQMWFEESA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
E [auth A]
F [auth A]
G [auth A]
I [auth C]
L [auth B]
E [auth A],
F [auth A],
G [auth A],
I [auth C],
L [auth B],
O [auth D]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
CL
Query on CL

Download Ideal Coordinates CCD File 
H [auth A],
J [auth C],
K [auth C],
N [auth B]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
Modified Residues  3 Unique
IDChains TypeFormula2D DiagramParent
CME
Query on CME
A
L-PEPTIDE LINKINGC5 H11 N O3 S2CYS
CSX
Query on CSX
A
L-PEPTIDE LINKINGC3 H7 N O3 SCYS
SCH
Query on SCH
A
L-PEPTIDE LINKINGC4 H9 N O2 S2CYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.187 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 96.49α = 90
b = 96.52β = 90
c = 139.08γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
European UnionLSH-2005-2.2.0-8

Revision History  (Full details and data files)

  • Version 1.0: 2019-04-17
    Type: Initial release
  • Version 1.1: 2024-01-24
    Changes: Data collection, Database references, Refinement description