2ZOD

Crystal structure of selenophosphate synthetase from Aquifex aeolicus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.204 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure of selenophosphate synthetase essential for selenium incorporation into proteins and RNAs.

Itoh, Y.Sekine, S.Matsumoto, E.Akasaka, R.Takemoto, C.Shirouzu, M.Yokoyama, S.

(2009) J Mol Biol 385: 1456-1469

  • DOI: 10.1016/j.jmb.2008.08.042
  • Primary Citation of Related Structures:  
    2YYE, 2ZOD

  • PubMed Abstract: 
  • Selenophosphate synthetase (SPS) catalyzes the activation of selenide with adenosine 5'-triphosphate (ATP) to generate selenophosphate, the essential reactive selenium donor for the formation of selenocysteine (Sec) and 2-selenouridine residues in proteins and RNAs, respectively ...

    Selenophosphate synthetase (SPS) catalyzes the activation of selenide with adenosine 5'-triphosphate (ATP) to generate selenophosphate, the essential reactive selenium donor for the formation of selenocysteine (Sec) and 2-selenouridine residues in proteins and RNAs, respectively. Many SPS are themselves Sec-containing proteins, in which Sec replaces Cys in the catalytically essential position (Sec/Cys). We solved the crystal structures of Aquifex aeolicus SPS and its complex with adenosine 5'-(alpha,beta-methylene) triphosphate (AMPCPP). The ATP-binding site is formed at the subunit interface of the homodimer. Four Asp residues coordinate four metal ions to bind the phosphate groups of AMPCPP. In the free SPS structure, the two loop regions in the ATP-binding site are not ordered, and no enzyme-associated metal is observed. This suggests that ATP binding, metal binding, and the formation of their binding sites are interdependent. To identify the amino-acid residues that contribute to SPS activity, we prepared six mutants of SPS and examined their selenide-dependent ATP consumption. Mutational analyses revealed that Sec/Cys13 and Lys16 are essential. In SPS.AMPCPP, the N-terminal loop, including the two residues, assumes different conformations ("open" and "closed") between the two subunits. The AMPCPP gamma-phosphate group is solvent-accessible, suggesting that a putative nucleophile could attack the ATP gamma-phosphate group to generate selenophosphate and adenosine 5'-diphosphate (ADP). Selenide attached to Sec/Cys13 as -Se-Se(-)/-S-Se(-) could serve as the nucleophile in the "closed" conformation. A water molecule, fixed close to the beta-phosphate group, could function as the nucleophile in subsequent ADP hydrolysis to orthophosphate and adenosine 5'-monophosphate.


    Organizational Affiliation

    Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Selenide, water dikinaseA, B345Aquifex aeolicusMutation(s): 1 
Gene Names: selDaq_1030
EC: 2.7.9.3
Find proteins for O67139 (Aquifex aeolicus (strain VF5))
Explore O67139 
Go to UniProtKB:  O67139
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth A], D [auth B]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.204 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.277α = 90
b = 76.871β = 101.1
c = 84.26γ = 90
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-05-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2014-04-09
    Changes: Database references, Other