Molecular adaptations to cold in psychrophilic enzymes.
Psychrophiles or cold-loving organisms successfully colonize cold environments of the Earth's biosphere. To cope with the reduction of chemical reaction rates induced by low temperatures, these organisms synthesize enzymes characterized by a high catalytic activity at low temperatures associated, however, with low thermal stability. Thanks to recent advances provided by X-ray crystallography, protein engineering and biophysical studies, we are beginning to understand the molecular adaptations responsible for these properties which appear to be relatively diverse. The emerging picture suggests that psychrophilic enzymes utilize an improved flexibility of the structures involved in the catalytic cycle, whereas other protein regions if not implicated in catalysis may or may not be subjected to genetic drift.
Feller
G
G
Laboratory of Biochemistry, Institute of Chemistry B6, University of Liège, 4000 Liège, Belgium. gfeller@ulg.ac.be
D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D004252:DNA Mutational Analysis; D019020:Directed Molecular Evolution; D004795:Enzyme Stability; D004798:Enzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D040961:Genetic Drift; D006358:Hot Temperature; D007700:Kinetics; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013816:Thermodynamics
D001426:Bacterial Proteins; D004798:Enzymes; D011994:Recombinant Proteins