This family includes proteins that are related to the YscJ lipoprotein, and the amino terminus of FliF, the flageller M-ring protein. The members of the YscJ family are thought to be involved in secretion of several proteins. The FliF protein ring is thought to be part of the export apparatus for flageller proteins, based on the similarity to YscJ proteins [2].

1: MxiJ, a lipoprotein involved in secretion of Shigella Ipa invasins, is homologous to YscJ, a secretion factor of the Yersinia Yop proteins. Allaoui A, Sansonetti PJ, Parsot C; J Bacteriol 1992;174:7661-7669. PMID:1332940

2: A structural feature in the central channel of the bacterial flagellar FliF ring complex is implicated in type III protein export. Suzuki H, Yonekura K, Murata K, Hirai T, Oosawa K, Namba K; J Struct Biol 1998;124:104-114. PMID:10049798