Crystal Structure of B. subtilis PurS P21 Crystal Form

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.321 
  • R-Value Work: 0.248 
  • R-Value Observed: 0.249 

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This is version 1.3 of the entry. See complete history


A Model for the Bacillus subtilis Formylglycinamide Ribonucleotide Amidotransferase Multiprotein Complex

Anand, R.Hoskins, A.A.Bennett, E.M.Sintchak, M.D.Stubbe, J.Ealick, S.E.

(2004) Biochemistry 43: 10343-10352

  • DOI: https://doi.org/10.1021/bi0491292
  • Primary Citation of Related Structures:  
    1T4A, 1TWJ

  • PubMed Abstract: 

    Formylglycinamide ribonucleotide amidotransferase (FGAR-AT) catalyzes the conversion of formylglycinamide ribonucleotide (FGAR), ATP, and glutamine to formylglycinamidine ribonucleotide (FGAM), ADP, P(i), and glutamate in the fourth step of the purine biosynthetic pathway. PurL exists in two forms: large PurL (lgPurL) is a single chain, multidomain enzyme of about 1300 amino acids, whereas small PurL (smPurL) contains about 800 amino acids but requires two additional gene products, PurS and PurQ, for activity. smPurL contains the ATP and FGAR binding sites, PurQ is a glutaminase, and the function of PurS is just now becoming understood. We determined the structure of Bacillus subtilis PurS in two different crystal forms P2(1) and C2 at 2.5 and 2.0 A resolution, respectively. PurS forms a tight dimer with a central six-stranded beta-sheet flanked by four helices. In both the P2(1) and the C2 crystal forms, the quaternary structure of PurS is a tetramer. The concave faces of the PurS dimers interact via the C-terminal region to form a twelve-stranded beta-barrel with a hydrophilic core. We used the structure of PurS together with the structure of lgPurL from Salmonella typhimurium to construct a model of the PurS/smPurL/PurQ complex. The HisH (glutaminase) domain of imidazole glycerol phosphate synthetase was used as an additional model of PurQ. The model shows stoichiometry of 2PurS/smPurL/PurQ using a PurS dimer or 4PurS/2smPurL/2PurQ using a PurS tetramer. Both models place key conserved residues at the ATP/FGAR binding site and at a structural ADP binding site. The homology model is consistent with biochemical studies on the reconstituted complex.

  • Organizational Affiliation

    Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Hypothetical UPF0062 protein yexA
A, B, C, D
84Bacillus subtilisMutation(s): 0 
Gene Names: YEXABSU06460
Find proteins for P12049 (Bacillus subtilis (strain 168))
Explore P12049 
Go to UniProtKB:  P12049
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP12049
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.321 
  • R-Value Work: 0.248 
  • R-Value Observed: 0.249 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.905α = 90
b = 87.955β = 94.97
c = 52.679γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-08-31
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Refinement description