Enables tubulin-glutamic acid ligase activity. Involved in cilium assembly and protein polyglutamylation. Acts upstream of or within angiogenesis; axoneme assembly; and neural crest cell migration. Predicted to be located in centriole and cilium. Predicted to be active in ciliary basal body. Is expressed in several structures, including Kupffer's vesicle; forerunner cell group; immature eye; nervous system; and pronephric duct. Human ortholog(s) of this gene implicated in Joubert syndrome 15. Orthologous to human CEP41 (centrosomal protein 41).