Computation of enzyme cold adaptation

Earth has several environments that are potentially hostile to life. The survival of organisms has required the expression of proteins that are adapted to function under extreme temperature, pH, pressure or ionic strength. However, the origin of such adaptations remains, in most cases, an open question. This Review presents a detailed analysis of the specialized enzymes that are able to maintain high catalytic rates at low temperatures and highlights the important role that computational studies have in uncovering the evolutionary principles behind the cold adaptation of enzymes. Although often highly homologous to their mesophilic counterparts, these cold-adapted enzymes have characteristic and universal properties that reflect their evolutionary optimization. In addition to exhibiting maximum reaction rates at lower temperatures, cold-adapted enzymes are more heat-labile and their catalytic mechanisms have distinct signatures in terms of the thermodynamic activation parameters. The structural origins of these properties have been elusive but are hypothesized to be related to protein flexibility.