1JR2

Structure of Uroporphyrinogen III Synthase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.84 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structure of human uroporphyrinogen III synthase.

Mathews, M.A.Schubert, H.L.Whitby, F.G.Alexander, K.J.Schadick, K.Bergonia, H.A.Phillips, J.D.Hill, C.P.

(2001) EMBO J. 20: 5832-5839

  • DOI: 10.1093/emboj/20.21.5832

  • PubMed Abstract: 
  • Uroporphyrinogen III synthase, U3S, the fourth enzyme in the porphyrin biosynthetic pathway, catalyzes cyclization of the linear tetrapyrrole, hydroxymethylbilane, to the macrocyclic uroporphyrino gen III, which is used in several different pathways ...

    Uroporphyrinogen III synthase, U3S, the fourth enzyme in the porphyrin biosynthetic pathway, catalyzes cyclization of the linear tetrapyrrole, hydroxymethylbilane, to the macrocyclic uroporphyrino gen III, which is used in several different pathways to form heme, siroheme, chlorophyll, F(430) and vitamin B(12). U3S activity is essential in all organisms, and decreased activity in humans leads to the autosomal recessive disorder congenital erythropoetic porphyria. We have determined the crystal structure of recombinant human U3S at 1.85 A resolution. The protein folds into two alpha/beta domains connected by a beta-ladder. The active site appears to be located between the domains, and variations in relative domain positions observed between crystallographically independent molecules indicates the presence of flexibility that may be important in the catalytic cycle. Possible mechanisms of catalysis were probed by mutating each of the four invariant residues in the protein that have titratable side chains. Additionally, six other highly conserved and titratable side chains were also mutated. In no case, however, did one of these mutations abolish enzyme activity, suggesting that the mechanism does not require acid/base catalysis.


    Organizational Affiliation

    Department of Biochemistry, University of Utah School of Medicine, 50 N. Medical Drive, Salt Lake City, UT 84132, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
UROPORPHYRINOGEN-III SYNTHASE
A, B
286Homo sapiensGene Names: UROS
EC: 4.2.1.75
Find proteins for P10746 (Homo sapiens)
Go to Gene View: UROS
Go to UniProtKB:  P10746
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.84 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.200 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 39.852α = 80.47
b = 59.251β = 73.32
c = 61.944γ = 88.33
Software Package:
Software NamePurpose
SOLVEphasing
DENZOdata reduction
SHARPphasing
REFMACrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-11-07
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Advisory, Refinement description