Regulates microtubule dynamics in uterine muscle cells. RNAi-mediated knockdown at the L1 larval stage causes a reduction in egg-laying, likely due to a defect in the egg-laying apparatus muscles and in hermaphrodite specific neurons. Belongs to the tubulin--tyrosine ligase family. Although it belongs to the tubulin--tyrosine ligase family, the TTL domain lacks some of the ATP binding sites predicted to be essential for TTL activity (By similarity). Lacks tyrosine ligase activity in vitro (By similarity). Lacks glutamylation activity in vitro (By similarity).