Hot Spots for Allosteric Regulation on Protein Surfaces

Recent work indicates a general architecture for proteins in which sparse networks of physically contiguous and coevolving amino acids underlie basic aspects of structure and function. These networks, termed sectors, are spatially organized such that active sites are linked to many surface sites distributed throughout the structure. Using the metabolic enzyme dihydrofolate reductase as a model system, we show that: (1) the sector is strongly correlated to a network of residues undergoing millisecond conformational fluctuations associated with enzyme catalysis, and (2) sector-connected surface sites are statistically preferred locations for the emergence of allosteric control in vivo. Thus, sectors represent an evolutionarily conserved “wiring” mechanism that can enable perturbations at specific surface positions to rapidly initiate conformational control over protein function. These findings suggest that sectors enable the evolution of intermolecular communication and regulation. [Display omitted] ► The protein sector in DHFR is associated with the dynamics underlying catalysis ► Sectors connect some surface positions to the active site ► Sector-connected surface sites are hot spots for allosteric regulation ► This preorganized wiring might facilitate evolution of interprotein communication Protein sectors, networks of physically contiguous and coevolving amino acids, facilitate the emergence of allosteric regulation, as demonstrated with chimeric proteins. The findings suggest that sectors also naturally enable the evolution of intermolecular communication.