Trapped intermediate state of plant pyruvate phosphate dikinase indicates substeps in catalytic swiveling domain mechanism

Protein Sci. 2017 Aug;26(8):1667-1673. doi: 10.1002/pro.3184. Epub 2017 May 12.


Pyruvate phosphate dikinase (PPDK) is an essential enzyme of both the C4 photosynthetic pathway and cellular energy metabolism of some bacteria and unicellular protists. In C4 plants, it catalyzes the ATP- and Pi -dependent formation of phosphoenolpyruvate (PEP) while in bacteria and protozoa the ATP-forming direction is used. PPDK is composed out of three distinct domains and exhibits one of the largest single domain movements known today during its catalytic cycle. However, little information about potential intermediate steps of this movement was available. A recent study resolved a discrete intermediate step of PPDK's swiveling movement, shedding light on the details of this intriguing mechanism. Here we present an additional structural intermediate that possibly represents another crucial step in the catalytic cycle of PPDK, providing means to get a more detailed understanding of PPDK's mode of function.

Keywords: C4 photosynthesis; catalytic intermediate; pyruvate phosphate dikinase; swiveling domain mechanism.

MeSH terms

  • Biocatalysis
  • Catalytic Domain
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Flaveria / chemistry*
  • Flaveria / enzymology
  • Gene Expression
  • Models, Molecular
  • Phosphoenolpyruvate / chemistry*
  • Phosphoenolpyruvate / metabolism
  • Plant Proteins / chemistry*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Domains
  • Pyruvate, Orthophosphate Dikinase / chemistry*
  • Pyruvate, Orthophosphate Dikinase / genetics
  • Pyruvate, Orthophosphate Dikinase / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Substrate Specificity
  • Thermodynamics


  • Plant Proteins
  • Recombinant Proteins
  • Phosphoenolpyruvate
  • Pyruvate, Orthophosphate Dikinase