Substrate-selective channel for a variety of different sugars. Could potentially facilitate the diffusion of diverse compounds, dependent on the presence of a hydroxyl group, but is presumably restricted to carbohydrates. Involved in the transport of glucose, mannitol, fructose and glycerol (sugars able to support the growth of P.aeruginosa). Facilitates glucose diffusion across the outer membrane. By glucose. Belongs to the OprB family.