The function of Ensembl gene identifier ENSG00000120440 (TTLL2, tubulin tyrosine ligase like 2) is as follows. Probable tubulin polyglutamylase that generates side chains of glutamate on the gamma-carboxyl group of specific glutamate residues within the C-terminal tail of target proteins (By similarity). Similar to TTLL1, may acquire enzymatic activity only in complex with other proteins as it is most likely lacking domains important for autonomous activity (By similarity). Probably involved in the side-chain initiation step of the polyglutamylation reaction rather than the elongation step (By similarity). {ECO:0000250|UniProtKB:A4Q9E4, ECO:0000250|UniProtKB:Q91V51}.