Modulates the polysaccharide chain length of enterobacterial common antigen (ECA). Required for the assembly of the phosphoglyceride-linked form of ECA (ECA(PG)) and the water-soluble cyclic form of ECA (ECA(CYC)). Bacterial outer membrane biogenesis; enterobacterial common antigen biosynthesis. Probably part of a complex composed of WzxE, WzyE and WzzE. Null mutation abolishes ECA(CYC) synthesis. Belongs to the WzzB/Cld/Rol family. Extended N-terminus.