3EAW

Replacement of Val3 in Human Thymidylate Synthase Affects Its Kinetic Properties and Intracellular Stability


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.86 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.230 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Replacement of Val3 in human thymidylate synthase affects its kinetic properties and intracellular stability .

Huang, X.Gibson, L.M.Bell, B.J.Lovelace, L.L.Pena, M.M.Berger, F.G.Berger, S.H.Lebioda, L.

(2010) Biochemistry 49: 2475-2482

  • DOI: 10.1021/bi901457e
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Human and other mammalian thymidylate synthase (TS) enzymes have an N-terminal extension of approximately 27 amino acids that is not present in bacterial TSs. The extension, which is disordered in all reported crystal structures of TSs, has been cons ...

    Human and other mammalian thymidylate synthase (TS) enzymes have an N-terminal extension of approximately 27 amino acids that is not present in bacterial TSs. The extension, which is disordered in all reported crystal structures of TSs, has been considered to play a primary role in protein turnover but not in catalytic activity. In mammalian cells, the variant V3A has a half-life similar to that of wild-type human TS (wt hTS) while V3T is much more stable; V3L, V3F, and V3Y have half-lives approximately half of that for wt hTS. Catalytic turnover rates for most Val3 mutants are only slightly diminished, as expected. However, two mutants, V3L and V3F, have strongly compromised dUMP binding, with K(m,app) values increased by factors of 47 and 58, respectively. For V3L, this observation can be explained by stabilization of the inactive conformation of the loop of residues 181-197, which prevents substrate binding. In the crystal structure of V3L, electron density corresponding to a leucine residue is present in a position that stabilizes the loop of residues 181-197 in the inactive conformation. Since this density is not observed in other mutants and all other leucine residues are ordered in this structure, it is likely that this density represents Leu3. In the crystal structure of a V3F.FdUMP binary complex, the nucleotide is bound in an alternative mode to that proposed for the catalytic complex, indicating that the high K(m,app) value is caused not by stabilization of the inactive conformer but by substrate binding in a nonproductive, inhibitory site. These observations show that the N-terminal extension affects the conformational state of the hTS catalytic region. Each of the mechanisms leading to the high K(m,app) values can be exploited to facilitate design of compounds acting as allosteric inhibitors of hTS.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Thymidylate synthase
X
313Homo sapiensMutation(s): 1 
Gene Names: TYMS (TS)
EC: 2.1.1.45
Find proteins for P04818 (Homo sapiens)
Go to Gene View: TYMS
Go to UniProtKB:  P04818
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
X
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
EDO
Query on EDO

Download SDF File 
Download CCD File 
X
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CME
Query on CME
X
L-PEPTIDE LINKINGC5 H11 N O3 S2CYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.86 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.230 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 95.704α = 90.00
b = 95.704β = 90.00
c = 81.940γ = 120.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
HKL-2000data collection
CNSphasing
REFMACrefinement
DENZOdata reduction
HKL-2000data scaling
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-03-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-10-25
    Type: Refinement description