Structural studies of Chlamydomonas reinhardtii IFT-B show that the complex consists of two subcomplexes: IFT-B1 (core) and IFT-B2 (peripheral). IFT-B2 interacts with microtubules and linking them to IFT-B1 subcomplex via IFT88/52. All 6 orthologous subunits of the IFT-B2 complex (Cluap1, IFT54, Oseg5, Oseg2, IFT20 and IFT57) are present in D.mel, but orthologs for IFT74, IFT25, IFT81, IFT27, IFT22, comprising approximately half of the subunits of IFT-B1, have not been identified (FBrf0223491).