Probable glycylase which modifies tubulin, generating side chains of glycine on the gamma-carboxyl groups of specific glutamate residues within the C-terminal tail of tubulin. Mainly present in assembling locomotory cilia. Cells lacking TTLL3A, TTLL3B, TTLL3C, TTLL3D, TTLL3E and TTLL3F display shortened axonemes that are resistant to paclitaxel, indicating that tubulin glycylation changes the lattice properties of axonemal microtubules. Axonemes are however normal at the ultrastructural level.