Novel stereospecificity of the L-arabinose-binding protein.

Tertiary structure refinement at 1.7 A resolution of the liganded form of L-arabinose-binding protein from Escherichia coli has revealed a novel binding site geometry which accommodates both alpha- and beta-anomers of L-arabinose. This detailed structure analysis provides new understanding of protein-sugar interaction, the process by which the binding protein minimizes the difference in the stability of the two bound sugar anomers, and the roles of periplasmic binding proteins in active transport.