The crystal structure, mutagenesis, and activity studies reveal that patatin is a lipid acyl hydrolase with a Ser-Asp catalytic dyad

Biochemistry. 2003 Jun 10;42(22):6696-708. doi: 10.1021/bi027156r.


Patatin is a nonspecific lipid acyl hydrolase that accounts for approximately 40% of the total soluble protein in mature potato tubers, and it has potent insecticidal activity against the corn rootworm. We determined the X-ray crystal structure of a His-tagged variant of an isozyme of patatin, Pat17, to 2.2 A resolution, employing SeMet multiwavelength anomalous dispersion (MAD) phasing methods. The patatin crystal structure has three molecules in the asymmetric unit, an R-factor of 22.0%, and an R(free) of 27.2% (for 10% of the data not included in the refinement) and includes 498 water molecules. The structure notably revealed that patatin has a Ser-Asp catalytic dyad and an active site like that of human cytosolic phospholipase A(2) (cPLA(2)) [Dessen, A., et al. (1999) Cell 97, 349-360]. In addition, patatin has a folding topology related to that of the catalytic domain of cPLA(2) and unlike the canonical alpha/beta-hydrolase fold. The structure confirms our site-directed mutagenesis and bioactivity data that initially suggested patatin possessed a Ser-Asp catalytic dyad. Alanine-scanning mutagenesis revealed that Ser77 and Asp215 were critical for both esterase and bioactivity, consistent with prior work implicating a Ser residue [Strickland, J. H., et al. (1995) Plant Physiol. 109, 667-674] and a Ser-Asp dyad [Hirschberg, H. J. H. B., et al. (2001) Eur. J. Biochem. 268, 5037-5044] in patatin's catalytic activity. The crystal structure aids the understanding of other structure-function relationships in patatin. Patatin does not display interfacial activation, a hallmark feature of lipases, and this is likely due to the fact that it lacks a flexible lid that can shield the active site.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alanine / genetics
  • Amino Acid Substitution / genetics
  • Animals
  • Aspartic Acid / genetics
  • Aspartic Acid / metabolism*
  • Carboxylic Ester Hydrolases / chemistry*
  • Carboxylic Ester Hydrolases / genetics
  • Carboxylic Ester Hydrolases / metabolism*
  • Carboxylic Ester Hydrolases / pharmacology
  • Catalytic Domain / genetics
  • Cloning, Molecular
  • Coleoptera / drug effects
  • Crystallography, X-Ray
  • Humans
  • Isoenzymes / chemistry
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Isoenzymes / pharmacology
  • Larva
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Phospholipases A / genetics
  • Pichia / metabolism
  • Plant Proteins / chemistry*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Proteins / pharmacology
  • Protein Structure, Secondary
  • Serine / genetics
  • Serine / metabolism*


  • Isoenzymes
  • Plant Proteins
  • patatin protein, Solanum tuberosum
  • Aspartic Acid
  • Serine
  • Carboxylic Ester Hydrolases
  • Phospholipases A
  • Alanine