OBSOLETE. A porin of the bacterial outer membrane that forms transmembrane pores and transports relatively large molecules from the external milieu to the periplasm in an energized process. Energizing of transport across the outer membrane requires a heterotrimeric complex of proteins, the TonB-ExbB-ExbD complex, or in some cases, the TolA-TolQ-TolR complex. Energizing requires proton motive force across the cytoplasmic membrane.