Crystallographic snapshot of the Escherichia coli EnvZ histidine kinase in an active conformation

J Struct Biol. 2014 Jun;186(3):376-9. doi: 10.1016/j.jsb.2014.03.014. Epub 2014 Mar 26.


Sensor histidine kinases are important sensors of the extracellular environment and relay signals via conformational changes that trigger autophosphorylation of the kinase and subsequent phosphorylation of a response regulator. The exact mechanism and the regulation of this protein family are a matter of ongoing investigation. Here we present a crystal structure of a functional chimeric protein encompassing the entire catalytic part of the Escherichia coli EnvZ histidine kinase, fused to the HAMP domain of the Archaeoglobus fulgidus Af1503 receptor. The construct is thus equivalent to the full cytosolic part of EnvZ. The structure shows a putatively active conformation of the catalytic domain and gives insight into how this conformation could be brought about in response to sensory input. Our analysis suggests a sequential flip-flop autokinase mechanism.

Keywords: CA domain; DHp domain; HAMP domain; Phosphoryl transfer; Two-component signal transduction system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Archaeal Proteins / chemistry
  • Archaeal Proteins / genetics
  • Archaeal Proteins / metabolism
  • Archaeoglobus fulgidus / chemistry
  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Catalytic Domain
  • Cytosol / metabolism
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Histidine Kinase
  • Models, Molecular
  • Molecular Sequence Data
  • Multienzyme Complexes / chemistry*
  • Multienzyme Complexes / genetics
  • Multienzyme Complexes / metabolism*
  • Protein Conformation
  • Protein Kinases / chemistry
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Signal Transduction


  • Archaeal Proteins
  • Bacterial Outer Membrane Proteins
  • Escherichia coli Proteins
  • Multienzyme Complexes
  • Recombinant Proteins
  • Protein Kinases
  • Histidine Kinase
  • envZ protein, E coli

Associated data

  • PDB/4CTI