Centrosomal protein CEP104 localises to the distal end of centrioles that interacts through its N- and C-terminal region, respectively, with the distal end proteins Cep97 and CP110 [1]. It is required for ciliogenesis and for structural integrity at the ciliary tip, being involved in regulating microtubule length in cilia. This is a multidomain protein that consists of an N-terminal all-beta domain, a central all-alpha-helical TOG domain and a C-terminal array of four zinc fingers domain [1]. This entry represents the central tubulin-binding TOG domain, consisting of HEAT repeats [1,2]. The sequence of TOG domains is quite divergent but the structure is conserved with some variation at the N and C-terminal [3]. This entry also includes MEKK1 which has a TOG domain more closely related to that in CEP104, as they share a similar pair of arginine-rich C-terminal helices relative to canonical TOGs [3]. MEKK1 TOG preferentially binds curved tubulin heterodimers [3].

1: The Ciliopathy-Associated Cep104 Protein Interacts with Tubulin and Nek1 Kinase. Al-Jassar C, Andreeva A, Barnabas DD, McLaughlin SH, Johnson CM, Yu M, van Breugel M; Structure. 2017;25:146-156. PMID:28017521

2: Biophysical and Structural Characterization of the Centriolar Protein Cep104 Interaction Network. Rezabkova L, Kraatz SH, Akhmanova A, Steinmetz MO, Kammerer RA; J Biol Chem. 2016;291:18496-18504. PMID:27402853

3: A cryptic tubulin-binding domain links MEKK1 to curved tubulin protomers. Filipcik P, Latham SL, Cadell AL, Day CL, Croucher DR, Mace PD; Proc Natl Acad Sci U S A. 2020;117:21308-21318. PMID:32817551