1BQ2

E. COLI THYMIDYLATE SYNTHASE MUTANT N177A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Inactivity of N229A thymidylate synthase due to water-mediated effects: isolating a late stage in methyl transfer.

Reyes, C.L.Sage, C.R.Rutenber, E.E.Nissen, R.M.Finer-Moore, J.S.Stroud, R.M.

(1998) J Mol Biol 284: 699-712

  • DOI: 10.1006/jmbi.1998.2205
  • Primary Citation of Related Structures:  
    1BQ2, 1BQ1

  • PubMed Abstract: 
  • Mutation of thymidylate synthase N229(177) to alanine results in an essentially inactive enzyme, yet it leads to formation of a stable ternary complex. The kinetics of N229(177)A show that kcat for Escherichia coli is reduced by 200-fold while the Km for dUMP is increased 200-fold and the Km for folate increased by tenfold versus the wild-type enzyme ...

    Mutation of thymidylate synthase N229(177) to alanine results in an essentially inactive enzyme, yet it leads to formation of a stable ternary complex. The kinetics of N229(177)A show that kcat for Escherichia coli is reduced by 200-fold while the Km for dUMP is increased 200-fold and the Km for folate increased by tenfold versus the wild-type enzyme. The crystal structures of N229(177)A in complex with dUMP and CB3717, and in complex with dUMP alone are determined at 2.4 A, and 2.5 A resolution. These structures identify the covalently bound ternary complex and show how N229(177)A traps an intermediate, and so becomes inactive in a later step of the reaction. Since the smaller alanine side-chain at N229(177)A does not directly sterically impair binding of ligands, the structures implicate, and place quantitative limits on the involvement of the structured water network in the active site of thymidylate synthase in both catalysis and in determining the binding affinity for dUMP (in contrast, the N229(177)V mutation in Lactobacillus casei has minimal effect on activity).


    Organizational Affiliation

    Graduate Group in Biophysics, University of California, San Francisco 94143-0448, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
THYMIDYLATE SYNTHASEA264Escherichia coliMutation(s): 1 
Gene Names: thyA
EC: 2.1.1.45
UniProt
Find proteins for P0A884 (Escherichia coli (strain K12))
Explore P0A884 
Go to UniProtKB:  P0A884
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download Ideal Coordinates CCD File 
B [auth A]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 
  • Space Group: I 21 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 133.06α = 90
b = 133.06β = 90
c = 133.06γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1999-04-27
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance