Unravelling the mechanisms of adaptation to high pressure in proteins

Life is thought to have appeared in the depth of the sea, under high hydrostatic pressure. Nowadays, it is known that the deep biosphere hosts a myriad of life forms thriving under high pressure conditions. However, the evolutionary mechanisms leading to their adaptation are still not known. Here we show the molecular bases of these mechanisms through a neutron scattering study of two orthologous proteins. We observed that pressure adaptation involves the decoupling of protein-water dynamics and the elimination of cavities in the protein core. This is achieved by an enrichment of acidic residues on the protein surface and by the use of bulkier hydrophobic residues in the core. These findings will be the starting point in the search of a complete genomic model explaining high pressure adaptation.