From hyperthermophiles to psychrophiles: the structural basis of temperature stability of the amino acid dehydrogenases.

The determination and comparison of the structures of a number of glutamate dehydrogenases that span the spectrum of thermal stability from mesophiles to hyperthermophiles have revealed that the formation of extended ion-pair networks is a major stabilizing feature in the adaptation of the organism to life at 100 degrees C. Analysis of the structures of other hyperthermophilic proteins has shown that ion-pair networks also play roles in their stabilization, including the phosphoglucose isomerase from Pyrococcus furiosus and the maltosyltransferase from Thermotoga maritima.