Experimental Data Snapshot

  • Resolution: 1.70 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.151 
  • R-Value Observed: 0.151 

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This is version 1.3 of the entry. See complete history


Crystal structures of a unique thermal-stable thymidylate synthase from Bacillus subtilis.

Stout, T.J.Schellenberger, U.Santi, D.V.Stroud, R.M.

(1998) Biochemistry 37: 14736-14747

  • DOI: https://doi.org/10.1021/bi981270l
  • Primary Citation of Related Structures:  
    1BKO, 1BKP, 1BSF, 1BSP

  • PubMed Abstract: 

    Unlike all other organisms studied to date, Bacillus subtilis expresses two different thymidylate synthases: bsTS-A and bsTS-B. bsTS-A displays enhanced enzymatic and structural thermal stability uncharacteristic of most TSs. Despite the high level of TS conservation across most species, bsTS-A shares low sequence identity (<40%) with the majority of TSs from other organisms. This TS and the TSs from Lactococcus lactis and phage Phi3T-to which it is most similar-have been of interest for some time since, by structure-based sequence alignment, they appear to lack several key residues shown by mutagenesis to be essential to enzymatic function [Greene, P. J., Yu, P. L., Zhao, J., Schiffer, C. A., and Santi, D. (1994) Protein Sci. 3, 1114-6]. In addition, bsTS-A demonstrates specific activity 2-3-fold higher than TS from Lactobacillus casei or Escherichia coli. We have solved the crystal structure of this unusual TS in four crystal forms to a maximum resolution of 1.7 A. Each of these crystal forms contains either one or two noncrystallographically related dimers. Stabilization of the beta-sheet dimer interface through a dramatic architecture of buttressed internal salt bridges maintains the structural integrity of bsTS-A at elevated temperatures. Melting curves of TSs from L. casei and E. coli are compared to that of TS-A from B. subtilis and correlated with numbers of hydrogen bonds, salt bridges, and the numbers of interactions localized to the dimer interface. Analysis of this structure will shed light on the conservation of function across diversity of sequence, as well as provide insights into the thermal stabilization of a highly conserved enzyme.

  • Organizational Affiliation

    Department of Biochemistry, School of Medicine, University of California, San Francisco 94143-0448, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
278Bacillus subtilisMutation(s): 0 
Gene Names: THYA
Find proteins for P0CI79 (Bacillus subtilis (strain 168))
Explore P0CI79 
Go to UniProtKB:  P0CI79
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0CI79
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.70 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.151 
  • R-Value Observed: 0.151 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.94α = 90
b = 81.63β = 92.52
c = 64.79γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1999-02-02
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-02
    Changes: Database references, Other, Refinement description