Structures and analysis of highly homologous psychrophilic, mesophilic, and thermophilic adenylate kinases

J Biol Chem. 2004 Jul 2;279(27):28202-8. doi: 10.1074/jbc.M401865200. Epub 2004 Apr 20.

Abstract

The crystal structures of adenylate kinases from the psychrophile Bacillus globisporus and the mesophile Bacillus subtilis have been solved and compared with that from the thermophile Bacillus stearothermophilus. This is the first example we know of where a trio of protein structures has been solved that have the same number of amino acids and a high level of identity (66-74%) and yet come from organisms with different operating temperatures. The enzymes were characterized for their own thermal denaturation and inactivation, and they exhibited the same temperature preferences as their source organisms. The structures of the three highly homologous, dynamic proteins with different temperature-activity profiles provide an opportunity to explore a molecular mechanism of cold and heat adaptation. Their analysis suggests that the maintenance of the balance between stability and flexibility is crucial for proteins to function at their environmental temperatures, and it is achieved by the modification of intramolecular interactions in the process of temperature adaptation.

Publication types

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

MeSH terms

  • Adenylate Kinase / chemistry*
  • Amino Acid Sequence
  • Bacillus / enzymology
  • Bacillus subtilis / enzymology
  • Calorimetry, Differential Scanning
  • Cloning, Molecular
  • Cold Temperature
  • Crystallography, X-Ray
  • Escherichia coli / metabolism
  • Geobacillus stearothermophilus / enzymology
  • Hot Temperature
  • Hydrogen Bonding
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Conformation
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Temperature
  • Zinc / chemistry

Substances

  • Adenylate Kinase
  • Zinc

Associated data

  • PDB/1S3G
  • PDB/AP3J