1NJB

THYMIDYLATE SYNTHASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.74 Å
  • R-Value Work: 0.185 
  • R-Value Observed: 0.185 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Partitioning roles of side chains in affinity, orientation, and catalysis with structures for mutant complexes: asparagine-229 in thymidylate synthase.

Finer-Moore, J.S.Liu, L.Schafmeister, C.E.Birdsall, D.L.Mau, T.Santi, D.V.Stroud, R.M.

(1996) Biochemistry 35: 5125-5136

  • DOI: https://doi.org/10.1021/bi952751x
  • Primary Citation of Related Structures:  
    1NJA, 1NJB, 1NJC, 1NJD, 1NJE

  • PubMed Abstract: 

    Thymidylate synthase (TS) methylates only dUMP, not dCMP. The crystal structure of TS.dCMP shows sCMP 4-NH2 excluded from the space between Asn-229 and His-199 by the hydrogen bonding and steric properties and Asn-229. Consequently, 6-C of dCMP is over 4 A from the active site sulfhydryl. The Asn-229 side chain is prevented from flipping 180 degrees to and orientation the could hydrogen bond to dCMP by a hydrogen bond network between conserved residues. Thus, the specific binding of dUMP by TS results from occlusion of competing substrates by steric and electronic effects of residues in the active site cavity. When Asn-229 is replaced by a cysteine, the Cys-229 S gamma rotates out of the active site, and the mutant enzyme binds both dCMP and dUMP tightly but does not methylate dCMP. Thus simply admitting dCMP into the dUMP binding site of TS is not sufficient for methylation of dCMP. Structures of nucleotide complexes of TS N229D provide a reasonable explanation for the preferential methylation of dCMP instead of dUMP by this mutant. In TS N229D.dCMP, Asp-229 forms hydrogen bonds to 3-N and 40NH2 of dCMP. Neither the Asp-229 carboxyl moiety nor ordered water appears to hydrogen bond to 4-O of dUMP. Hydrogen bonds to 4-O (or 4-NH2) have been proposed to stabilize reaction intermediates. If their absence in TS N229D.dUMP persists in the ternary complex, it could explain the 10(4)-fold decrease in kcat/Km for dUMP.


  • Organizational Affiliation

    Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
THYMIDYLATE SYNTHASE316Lacticaseibacillus caseiMutation(s): 1 
Gene Names: N229C MUTANT OF CLONED L. CASE
EC: 2.1.1.45
UniProt
Find proteins for P00469 (Lacticaseibacillus casei)
Explore P00469 
Go to UniProtKB:  P00469
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00469
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
UMP
Query on UMP

Download Ideal Coordinates CCD File 
B [auth A]2'-DEOXYURIDINE 5'-MONOPHOSPHATE
C9 H13 N2 O8 P
JSRLJPSBLDHEIO-SHYZEUOFSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
UMP PDBBind:  1NJB Kd: 1600 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.74 Å
  • R-Value Work: 0.185 
  • R-Value Observed: 0.185 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.7α = 90
b = 78.7β = 90
c = 242.1γ = 120
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
XENGENdata reduction
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-10-14
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2021-11-03
    Changes: Database references, Derived calculations, Other
  • Version 1.4: 2024-02-14
    Changes: Data collection