2QB6

Saccharomyces cerevisiae cytosolic exopolyphosphatase, sulfate complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.159 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The crystal structure of the cytosolic exopolyphosphatase from Saccharomyces cerevisiae reveals the basis for substrate specificity.

Ugochukwu, E.Lovering, A.L.Mather, O.C.Young, T.W.White, S.A.

(2007) J Mol Biol 371: 1007-1021

  • DOI: https://doi.org/10.1016/j.jmb.2007.05.066
  • Primary Citation of Related Structures:  
    2QB6, 2QB7, 2QB8

  • PubMed Abstract: 

    Inorganic long-chain polyphosphate is a ubiquitous linear polymer in biology, consisting of many phosphate moieties linked by phosphoanhydride bonds. It is synthesized by polyphosphate kinase, and metabolised by a number of enzymes, including exo- and endopolyphosphatases. The Saccharomyces cerevisiae gene PPX1 encodes for a 45 kDa, metal-dependent, cytosolic exopolyphosphatase that processively cleaves the terminal phosphate group from the polyphosphate chain, until inorganic pyrophosphate is all that remains. PPX1 belongs to the DHH family of phosphoesterases, which includes: family-2 inorganic pyrophosphatases, found in Gram-positive bacteria; prune, a cyclic AMPase; and RecJ, a single-stranded DNA exonuclease. We describe the high-resolution X-ray structures of yeast PPX1, solved using the multiple isomorphous replacement with anomalous scattering (MIRAS) technique, and its complexes with phosphate (1.6 A), sulphate (1.8 A) and ATP (1.9 A). Yeast PPX1 folds into two domains, and the structures reveal a strong similarity to the family-2 inorganic pyrophosphatases, particularly in the active-site region. A large, extended channel formed at the interface of the N and C-terminal domains is lined with positively charged amino acids and represents a conduit for polyphosphate and the site of phosphate hydrolysis. Structural comparisons with the inorganic pyrophosphatases and analysis of the ligand-bound complexes lead us to propose a hydrolysis mechanism. Finally, we discuss a structural basis for substrate selectivity and processivity.


  • Organizational Affiliation

    The School of Biosciences, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Exopolyphosphatase
A, B
397Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: PPX1YHR201C
EC: 3.6.1.11
UniProt
Find proteins for P38698 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P38698 
Go to UniProtKB:  P38698
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP38698
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A],
L [auth B]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
GOL
Query on GOL

Download Ideal Coordinates CCD File 
J [auth A]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
EDO
Query on EDO

Download Ideal Coordinates CCD File 
G [auth A],
H [auth A],
I [auth A]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
ACT
Query on ACT

Download Ideal Coordinates CCD File 
F [auth A]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
MN
Query on MN

Download Ideal Coordinates CCD File 
C [auth A],
K [auth B]
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.159 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.66α = 90
b = 82.914β = 90
c = 119.228γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
ADSCdata collection
MOSFLMdata reduction
SCALAdata scaling
SOLVEphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-12-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2024-02-21
    Changes: Data collection, Database references, Derived calculations