Physicochemical code for quinary protein interactions in Escherichia coli

Significance This study shows that the diffusive motions of proteins in live cells are by no means without control but follow simplistic physical−chemical rules that can be quantified and optimized through surface composition. Most strikingly, human proteins are observed to stick to the “foreign” environment of bacterial cells, whereas the bacterial analogue moves around freely. Even so, the human proteins can predictably be transformed to bacterial behavior with a few structurally benign surface mutations, and, conversely, the bacterial protein can be made to stick. The findings have not only fundamental implications for how protein function is controlled at the physical−chemical level but can also be used to adjust protein motion in Escherichia coli at will.