3QN0

Structure of 6-pyruvoyltetrahydropterin synthase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.34 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.224 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structural basis of a novel activity of bacterial 6-pyruvoyltetrahydropterin synthase homologues distinct from mammalian 6-pyruvoyltetrahydropterin synthase activity.

Seo, K.H.Zhuang, N.Park, Y.S.Park, K.H.Lee, K.H.

(2014) Acta Crystallogr D Biol Crystallogr 70: 1212-1223

  • DOI: 10.1107/S1399004714002016
  • Primary Citation of Related Structures:  
    3QN0, 3QN9, 3QNA

  • PubMed Abstract: 
  • Escherichia coli 6-carboxytetrahydropterin synthase (eCTPS), a homologue of 6-pyruvoyltetrahydropterin synthase (PTPS), possesses a much stronger catalytic activity to cleave the side chain of sepiapterin in vitro compared with genuine PTPS activity and catalyzes the conversion of dihydroneopterin triphosphate to 6-carboxy-5,6,7,8-tetrahydropterin in vivo ...

    Escherichia coli 6-carboxytetrahydropterin synthase (eCTPS), a homologue of 6-pyruvoyltetrahydropterin synthase (PTPS), possesses a much stronger catalytic activity to cleave the side chain of sepiapterin in vitro compared with genuine PTPS activity and catalyzes the conversion of dihydroneopterin triphosphate to 6-carboxy-5,6,7,8-tetrahydropterin in vivo. Crystal structures of wild-type apo eCTPS and of a Cys27Ala mutant eCTPS complexed with sepiapterin have been determined to 2.3 and 2.5 Å resolution, respectively. The structures are highly conserved at the active site and the Zn(2+) binding site. However, comparison of the eCTPS structures with those of mammalian PTPS homologues revealed that two specific residues, Trp51 and Phe55, that are not found in mammalian PTPS keep the substrate bound by stacking it with their side chains. Replacement of these two residues by site-directed mutagenesis to the residues Met and Leu, which are only found in mammalian PTPS, converted eCTPS to the mammalian PTPS activity. These studies confirm that these two aromatic residues in eCTPS play an essential role in stabilizing the substrate and in the specific enzyme activity that differs from the original PTPS activity. These aromatic residues Trp51 and Phe55 are a key signature of bacterial PTPS enzymes that distinguish them from mammalian PTPS homologues.


    Organizational Affiliation

    Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, Jinju 660-701, Republic of Korea.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
6-carboxy-5,6,7,8-tetrahydropterin synthase
A, B, C, D, E, F
A, B, C, D, E, F
141Escherichia coli BL21(DE3)Mutation(s): 0 
Gene Names: EcDH1_0923
EC: 4.1.2.50
UniProt
Find proteins for P65870 (Escherichia coli (strain K12))
Explore P65870 
Go to UniProtKB:  P65870
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP65870
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.34 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.224 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 112.853α = 90
b = 117.68β = 90
c = 153.828γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
AMoREphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-12-07
    Type: Initial release
  • Version 1.1: 2012-08-22
    Changes: Experimental preparation
  • Version 1.2: 2013-12-25
    Changes: Structure summary
  • Version 1.3: 2014-05-28
    Changes: Database references
  • Version 1.4: 2018-10-24
    Changes: Data collection, Source and taxonomy