2OFX

crystal structure of the APSK domain of human PAPSS1 in complex with ADPMg and PAPS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.192 

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This is version 1.2 of the entry. See complete history


Literature

Elucidation of the Active Conformation of the APS-Kinase Domain of Human PAPS Synthetase 1.

Sekulic, N.Dietrich, K.Paarmann, I.Ort, S.Konrad, M.Lavie, A.

(2007) J Mol Biol 367: 488-500

  • DOI: 10.1016/j.jmb.2007.01.025
  • Primary Citation of Related Structures:  
    2OFX, 2OFW

  • PubMed Abstract: 
  • Bifunctional human PAPS synthetase (PAPSS) catalyzes, in a two-step process, the formation of the activated sulfate carrier 3'-phosphoadenosine 5'-phosphosulfate (PAPS). The first reaction involves the formation of the 5'-adenosine phosphosulfate (APS) intermediate from ATP and inorganic sulfate ...

    Bifunctional human PAPS synthetase (PAPSS) catalyzes, in a two-step process, the formation of the activated sulfate carrier 3'-phosphoadenosine 5'-phosphosulfate (PAPS). The first reaction involves the formation of the 5'-adenosine phosphosulfate (APS) intermediate from ATP and inorganic sulfate. APS is then further phosphorylated on its 3'-hydroxyl group by an additional ATP molecule to generate PAPS. The former reaction is catalyzed by the ATP-sulfurylase domain and the latter by the APS-kinase domain. Here, we report the structure of the APS-kinase domain of PAPSS isoform 1 (PAPSS1) representing the Michaelis complex with the products ADP-Mg and PAPS. This structure provides a rare glimpse of the active conformation of an enzyme catalyzing phosphoryl transfer without resorting to substrate analogs, inactivating mutations, or catalytically non-competent conditions. Our structure shows the interactions involved in the binding of the magnesium ion and PAPS, thereby revealing residues critical for catalysis. The essential magnesium ion is observed bridging the phosphate groups of the products. This function of the metal ion is made possible by the DGDN-loop changing its conformation from that previously reported, and identifies these loop residues unambiguously as a Walker B motif. Furthermore, the second aspartate residue of this motif is the likely candidate for initiating nucleophilic attack on the ATP gamma-phosphate group by abstracting the proton from the 3'-hydroxyl group of the substrate APS. We report the structure of the APS-kinase domain of human PAPSS1 in complex with two APS molecules, demonstrating the ability of the ATP/ADP-binding site to bind APS. Both structures reveal extended N termini that approach the active site of the neighboring monomer. Together, these results significantly increase our understandings of how catalysis is achieved by APS-kinase.


    Organizational Affiliation

    Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, IL 60607, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthetase 1A, B207Homo sapiensMutation(s): 0 
Gene Names: PAPSS1ATPSK1PAPSS
EC: 2.7.1.25 (PDB Primary Data), 2.7.7.4 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for O43252 (Homo sapiens)
Explore O43252 
Go to UniProtKB:  O43252
PHAROS:  O43252
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.4α = 90
b = 63.32β = 114.38
c = 61.69γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
MOLREPphasing
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

  • Deposited Date: 2007-01-04 
  • Released Date: 2007-04-10 
  • Deposition Author(s): Sekulic, N., Lavie, A.

Revision History  (Full details and data files)

  • Version 1.0: 2007-04-10
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance