This family of proteins is found in flagella [1]. Proteins in this family are typically between 203 and 326 amino acids in length. There is a single completely conserved residue N that may be functionally important.

1: Proteomic analysis of a eukaryotic cilium. Pazour GJ, Agrin N, Leszyk J, Witman GB; J Cell Biol. 2005;170:103-113. PMID:15998802