3QNA

Crystal structure of a 6-pyruvoyltetrahydropterin synthase homologue from Esherichia coli complexed sepiapterin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.182 

wwPDB Validation 3D Report Full Report


This is version 1.2 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.,Sect.D 70: 1212-1223

  • DOI: 10.1107/S1399004714002016
  • Primary Citation of Related Structures:  

  • 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 ...

    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.,Division of Applied Life Science (BK21 Plus), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.,School of Biological Sciences, Inje University, Kimhae 621-749, Republic of Korea.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
6-carboxy-5,6,7,8-tetrahydropterin synthase
A, B, C, D, E, F
141Escherichia coli (strain B / BL21-DE3)Mutation(s): 1 
EC: 4.-.-.-
Find proteins for A0A140N8U9 (Escherichia coli (strain B / BL21-DE3))
Go to UniProtKB:  A0A140N8U9
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B, C, D, E, F
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
BIO
Query on BIO

Download SDF File 
Download CCD File 
A, B, C, D, E, F
BIOPTERIN
C9 H11 N5 O3
LHQIJBMDNUYRAM-AWFVSMACSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.182 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 112.714α = 90.00
b = 115.882β = 90.00
c = 155.185γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-2000data reduction
HKL-2000data collection
AMoREphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-12-07
    Type: Initial release
  • Version 1.1: 2013-12-25
    Type: Structure summary
  • Version 1.2: 2014-05-28
    Type: Database references