Evolution and structural dynamics of bacterial glycan binding adhesins

Infectious disease processes like bacterial adherence or the activity of secreted toxins frequently gain host and tissue specificity by glycan binding interactions with the host glycome. Recent functional and structural studies highlight the high niche specialization of bacterial lectins, but also reveal a remarkable plasticity in their glycan binding sites and mechanisms, to adapt to host glycome dynamics or changing environmental conditions at the site of infection. In this review we put emphasis on new structural insights in host adaptation and dynamics of bacterial carbohydrate binding adhesins and toxins in human pathogens like uropathogenic and enteropathogenic Escherichia coli, Helicobacter pylori, Yersinia pestis or Vibrio cholerae. Also, structure-aided drug design to counteract glycan-mediated host-pathogen interactions is coming of age, with the design of novel anti-adhesive compounds and (single-domain) antibodies that target glycan binding sites.