Atomic structures and function of periplasmic receptors for active transport and chemotaxis

Abstract

Well refined very-high-resolution structures of seven receptors that serve as primary components of bacterial active transport have provided a detailed new understanding of the atomic interactions associated with the specific recognition and binding of a variety of substances such as sulfate, phosphate, leucine, monosaccharides and oligosaccharides. Irrespective of the nature of the ligands, hydrogen bonds play a key and dominant role in molecular recognition and interactions. It is notable that no salt linkages, counterions or water molecules are associated with the bound charged ligands. These findings have important ramifications in several biological processes, notably active transport, rapid ion movement, and enzyme catalysis.