Members of the RTX superfamily (RTX (TC# 1.C.11); HrpZ (TC# 1.C.56) and CCT (TC# 1.C.57)) contain repeat sequences that are also found in autotransporters (e.g., 1.B.12.10.1 and 1.B.40.1.2) as well as TolA (2.C.1.2.1). These domains probably mediate protein-protein interactions.
