3D8T

Thermus thermophilus Uroporphyrinogen III Synthase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.192 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structure and mechanistic implications of a uroporphyrinogen III synthase-product complex.

Schubert, H.L.Phillips, J.D.Heroux, A.Hill, C.P.

(2008) Biochemistry 47: 8648-8655

  • DOI: 10.1021/bi800635y
  • Primary Citation of Related Structures:  
    3D8R, 3D8S, 3D8T, 3D8N

  • PubMed Abstract: 
  • Uroporphyrinogen III synthase (U3S) catalyzes the asymmetrical cyclization of a linear tetrapyrrole to form the physiologically relevant uroporphyrinogen III (uro'gen III) isomer during heme biosynthesis. Here, we report four apoenzyme and one product complex crystal structures of the Thermus thermophilus (HB27) U3S protein ...

    Uroporphyrinogen III synthase (U3S) catalyzes the asymmetrical cyclization of a linear tetrapyrrole to form the physiologically relevant uroporphyrinogen III (uro'gen III) isomer during heme biosynthesis. Here, we report four apoenzyme and one product complex crystal structures of the Thermus thermophilus (HB27) U3S protein. The overlay of eight crystallographically unique U3S molecules reveals a huge range of conformational flexibility, including a "closed" product complex. The product, uro'gen III, binds between the two domains and is held in place by a network of hydrogen bonds between the product's side chain carboxylates and the protein's main chain amides. Interactions of the product A and B ring carboxylate side chains with both structural domains of U3S appear to dictate the relative orientation of the domains in the closed enzyme conformation and likely remain intact during catalysis. The product C and D rings are less constrained in the structure, consistent with the conformational changes required for the catalytic cyclization with inversion of D ring orientation. A conserved tyrosine residue is potentially positioned to facilitate loss of a hydroxyl from the substrate to initiate the catalytic reaction.


    Organizational Affiliation

    Departments of Biochemistry and Internal Medicine, School of Medicine, University of Utah, Salt Lake City, Utah 84112, , USA. heidi@biochem.utah.edu



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Uroporphyrinogen-III synthaseA, B286Thermus thermophilus HB27Mutation(s): 0 
Gene Names: TT_C0312
EC: 4.2.1.75
Find proteins for Q72KM1 (Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039))
Explore Q72KM1 
Go to UniProtKB:  Q72KM1
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download Ideal Coordinates CCD File 
C [auth A], D [auth A], E [auth A], F [auth B]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 40.75α = 90
b = 89.957β = 101.32
c = 74.981γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2008-05-23 
  • Released Date: 2008-08-12 
  • Deposition Author(s): Schubert, H.L.

Revision History  (Full details and data files)

  • Version 1.0: 2008-08-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance