superfamily 26 OPM protein 1qjp Available protein structures: Pfam structures PDB RCSB PDB ; PDBe PDBsum structure summary OmpA-like transmembrane domain is an evolutionarily conserved domain of outer membrane {{dn|date=April 2012}] proteins. This domain consists of an eight-stranded beta barrel . [ 1 ] OmpA is the predominant cell surface antigen