A structure-based proposal for the catalytic mechanism of the bacterial acid phosphatase AphA belonging to the DDDD superfamily of phosphohydrolases

J Mol Biol. 2006 Jan 27;355(4):708-21. doi: 10.1016/j.jmb.2005.10.068. Epub 2005 Nov 10.

Abstract

The Escherichia coli gene aphA codes for a periplasmic acid phosphatase called AphA, belonging to class B bacterial phosphatases, which is part of the DDDD superfamily of phosphohydrolases. After our first report about its crystal structure, we have started a series of crystallographic studies aimed at understanding of the catalytic mechanism of the enzyme. Here, we report three crystal structures of the AphA enzyme in complex with the hydrolysis products of nucleoside monophosphate substrates and a fourth with a proposed intermediate analogue that appears to be covalently bound to the enzyme. Comparison with the native enzyme structure and with the available X-ray structures of different phosphatases provides clues about the enzyme chemistry and allows us to propose a catalytic mechanism for AphA, and to discuss it with respect to the mechanism of other bacterial and human phosphatases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / chemistry*
  • Acid Phosphatase / genetics
  • Acid Phosphatase / metabolism*
  • Adenosine Monophosphate / chemistry
  • Adenosine Monophosphate / metabolism
  • Amino Acid Sequence
  • Binding Sites
  • Catalysis
  • Conserved Sequence
  • Crystallography, X-Ray
  • Deoxycytidine Monophosphate / chemistry
  • Deoxycytidine Monophosphate / metabolism
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Ligands
  • Models, Molecular
  • Molecular Sequence Data
  • Phosphoric Monoester Hydrolases / chemistry*
  • Phosphoric Monoester Hydrolases / classification
  • Phosphoric Monoester Hydrolases / genetics
  • Phosphoric Monoester Hydrolases / metabolism*
  • Protein Structure, Quaternary
  • Protein Subunits / chemistry
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Structure-Activity Relationship
  • Substrate Specificity

Substances

  • Escherichia coli Proteins
  • Ligands
  • Protein Subunits
  • Deoxycytidine Monophosphate
  • Adenosine Monophosphate
  • Acid Phosphatase
  • AphA protein, E coli
  • Phosphoric Monoester Hydrolases

Associated data

  • PDB/1RMQ
  • PDB/1RMY
  • PDB/2B82
  • PDB/2B8J