– With TolR probably plays a role in maintaining the position of the peptidoglycan cell wall in the periplasm. Acts as a porin with low permeability that allows slow penetration of small solutes; an internal gate slows down solute passage.; Required for conjugation with F-type plasmids; probably serves as the mating receptor on recipient cells. OmpA Protein, E. coli O157:H7, Recombinant (His & SUMO) is expressed in E. coli expression system with N-6xHis-SUMO tag. The predicted molecular weight is 35.6 kDa and the accession number is P0A911.