Solution structure of the 40,000 Mr phosphoryl transfer complex between the N-terminal domain of enzyme I and HPr

Nat Struct Biol. 1999 Feb;6(2):166-73. doi: 10.1038/5854.


The solution structure of the first protein-protein complex of the bacterial phosphoenolpyruvate: sugar phosphotransferase system between the N-terminal domain of enzyme I (EIN) and the histidine-containing phosphocarrier protein HPr has been determined by NMR spectroscopy, including the use of residual dipolar couplings that provide long-range structural information. The complex between EIN and HPr is a classical example of surface complementarity, involving an essentially all helical interface, comprising helices 2, 2', 3 and 4 of the alpha-subdomain of EIN and helices 1 and 2 of HPr, that requires virtually no changes in conformation of the components relative to that in their respective free states. The specificity of the complex is dependent on the correct placement of both van der Waals and electrostatic contacts. The transition state can be formed with minimal changes in overall conformation, and is stabilized in favor of phosphorylated HPr, thereby accounting for the directionality of phosphoryl transfer.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins*
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Weight
  • Phosphoenolpyruvate Sugar Phosphotransferase System / chemistry*
  • Phosphotransferases (Nitrogenous Group Acceptor) / chemistry*
  • Protein Conformation
  • Sequence Homology, Amino Acid
  • Solutions


  • Bacterial Proteins
  • Solutions
  • Phosphoenolpyruvate Sugar Phosphotransferase System
  • phosphocarrier protein HPr
  • Phosphotransferases (Nitrogenous Group Acceptor)
  • phosphoenolpyruvate-protein phosphotransferase

Associated data

  • PDB/3EZA
  • PDB/3EZB
  • PDB/3EZC
  • PDB/3EZD