Structural characterization of the PTS IIA and IIB proteins associated with pneumococcal fucose utilization.

Streptococcus pneumoniae harbors a significant number of transporters, including phosphotransferase (PTS) systems, allowing the bacterium to utilize a number of different carbohydrates for metabolic and other purposes. The genes encoding for one PTS transport system in particular (EIIfuc ) are found within a fucose utilization operon in S. pneumoniae TIGR4. Here, we report the three-dimensional structures of IIAfuc and IIBfuc providing evidence that this PTS system belongs to the EIIman family. Additionally, the predicted metabolic pathway for this distinctive fucose utilization system suggests that EIIfuc transports the H-disaccharide blood group antigen, which would represent a novel PTS transporter specificity. Proteins 2017; 85:963-968. © 2016 Wiley Periodicals, Inc.