2QB7

Saccharomyces cerevisiae cytosolic exopolyphosphatase, phosphate complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.172 

wwPDB Validation 3D Report Full Report


This is version 1.1 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: 10.1016/j.jmb.2007.05.066
  • Primary Citation of Related Structures:  
    2QB8, 2QB7, 2QB6

  • 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- an ...

    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)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ExopolyphosphataseAB397Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: PPX1YHR201C
EC: 3.6.1.11
Find proteins for P38698 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P38698 
Go to UniProtKB:  P38698
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download CCD File 
A, B
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
EDO
Query on EDO

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A, B
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

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A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CO
Query on CO

Download CCD File 
A, B
COBALT (II) ION
Co
XLJKHNWPARRRJB-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.172 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.992α = 90
b = 83.039β = 90
c = 118.9γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
ADSCdata collection
MOSFLMdata reduction
SCALAdata scaling
REFMACphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-12-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance