1LRN

Aquifex aeolicus KDO8P synthase H185G mutant in complex with Cadmium


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.204 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Function of His185 in Aquifex aeolicus 3-Deoxy-D-manno-octulosonate 8-Phosphate Synthase

Wang, J.Duewel, H.S.Stuckey, J.A.Woodard, R.W.Gatti, D.L.

(2002) J Mol Biol 324: 205-214

  • DOI: 10.1016/s0022-2836(02)01096-3
  • Primary Citation of Related Structures:  
    1LRN, 1LRQ, 1LRO

  • PubMed Abstract: 
  • Aquifex aeolicus 3-deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) catalyzes the condensation of arabinose 5-phosphate (A5P) and phosphoenolpyruvate (PEP) by favoring the activation of a water molecule coordinated to the active-site metal ion. Cys11, His185, Glu222 and Asp233 are the other metal ligands ...

    Aquifex aeolicus 3-deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) catalyzes the condensation of arabinose 5-phosphate (A5P) and phosphoenolpyruvate (PEP) by favoring the activation of a water molecule coordinated to the active-site metal ion. Cys11, His185, Glu222 and Asp233 are the other metal ligands. Wild-type KDO8PS is purified with Zn(2+) or Fe(2+) in the active site, but maximal activity in vitro is achieved when the endogenous metal is replaced with Cd(2+). The H185G enzyme retains 8% of the wild-type activity. ICP mass spectrometry analysis indicates that loss of His185 decreases the enzyme affinity for Fe(2+), but not for Zn(2+). However, maximal activity is again achieved by substitution of the endogenous metal with Cd(2+). We have determined the X-ray structures of the Cd(2+) H185G enzyme in its substrate-free form, and in complex with PEP, and PEP plus A5P. These structures show a normal amount of Cd(2+) bound, suggesting that coordination by His185 is not essential to retain Cd(2+) in the active site. Nonetheless, there are significant changes in the coordination sphere of Cd(2+) with respect to the wild-type enzyme, as the carboxylate moiety of PEP binds directly to the metal ion and replaces water and His185 as ligands. These observations indicate that the primary function of His185 in A.aeolicus KDO8PS is to orient PEP in the active site of the enzyme in such a way that a water molecule on the sinister (si) side of PEP can be activated by direct coordination to the metal ion.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
KDO-8-phosphate synthetaseA, B267Aquifex aeolicusMutation(s): 1 
EC: 4.1.2.16 (PDB Primary Data), 2.5.1.55 (UniProt)
UniProt
Find proteins for O66496 (Aquifex aeolicus (strain VF5))
Explore O66496 
Go to UniProtKB:  O66496
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.204 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.382α = 90
b = 84.382β = 90
c = 159.767γ = 120
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-11-27
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description