Crystallographic evidence for noncoplanar catalytic aspartic acids in plasmepsin II resides in the Protein Data Bank

Acta Crystallogr D Biol Crystallogr. 2009 Mar;65(Pt 3):294-6. doi: 10.1107/S0907444908041632. Epub 2009 Feb 20.

Abstract

The carboxylate atoms of the two catalytic aspartic acid residues in aspartic proteases are nearly coplanar and in the uncomplexed form share an in-plane nucleophilic water molecule that is central to the mechanism of these enzymes. This note reports that while reviewing the electron-density maps derived from the deposited data for uncomplexed plasmepsin II from Plasmodium falciparum [Asojo et al. (2003), J. Mol. Biol. 327, 173-181; PDB code 1lf4], it was discovered that the aspartic acid residues in this structure should in fact be distinctly noncoplanar. The crystallographic model from the deposited coordinates has been re-refined against the 1.9 A resolution published diffraction data to an R(cryst) of 21.2% and an R(free) of 22.2%. The catalytic water molecule is present, but the plane of the carboxylate group of Asp214 is rotated by 66 degrees from its original position.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Aspartic Acid / chemistry*
  • Aspartic Acid Endopeptidases / chemistry*
  • Catalysis
  • Catalytic Domain
  • Crystallography, X-Ray
  • Electrons
  • Hydrogen Bonding
  • Models, Molecular
  • Plasmodium falciparum / enzymology*
  • Protein Conformation
  • Protozoan Proteins / chemistry*
  • Water / chemistry

Substances

  • Protozoan Proteins
  • Water
  • Aspartic Acid
  • Aspartic Acid Endopeptidases
  • plasmepsin II

Associated data

  • PDB/3F9Q
  • PDB/R3F9QSF