Catalytic tRNA acetyltransferase subunit of the elongator complex which is required for multiple tRNA modifications, including mcm5U (5-methoxycarbonylmethyl uridine), mcm5s2U (5-methoxycarbonylmethyl-2-thiouridine), and ncm5U (5-carbamoylmethyl uridine) (PubMed:29415125). In the elongator complex, acts as a tRNA uridine(34) acetyltransferase by mediating formation of carboxymethyluridine in the wobble base at position 34 in tRNAs (By similarity). May also act as a protein lysine acetyltransferase by mediating acetylation of target proteins; such activity is however unclear in vivo and recent evidences suggest that ELP3 primarily acts as a tRNA acetyltransferase (PubMed:29415125). Involved in neurogenesis: regulates the migration and branching of projection neurons in the developing cerebral cortex, through a process depending on alpha-tubulin acetylation (PubMed:19185337). Required for acetylation of GJA1 in the developing cerebral cortex (By similarity). acetyl-CoA + H2O + S-adenosyl-L-methionine + uridine(34) in tRNA = 5'-deoxyadenosine + carboxymethyluridine(34) in tRNA + CoA + 2 H(+) + L-methionine Binds 1 [4Fe-4S] cluster. The cluster is coordinated with 3 cysteines and an exchangeable S-adenosyl-L-methionine. tRNA modification; 5-methoxycarbonylmethyl-2-thiouridine-tRNA biosynthesis. Component of the elongator complex which consists of ELP1, ELP2, ELP3, ELP4, ELP5 and ELP6. ELP1, ELP2 and ELP3 form the elongator core complex (PubMed:11714725, PubMed:11818576, PubMed:19185337, PubMed:22854966, PubMed:25960406). Interacts with alpha-tubulin (PubMed:19185337). Expressed in the cerebellum and spinal motor neurons. Tyrosine-phosphorylated; phosphorylation on Tyr-202 does not affect elongator complex integrity or ELP3 protein stability (PubMed:31341009). Also serine/threonine-phosphorylated (PubMed:31341009). The gene represented in this entry may act as a disease modifier. Belongs to the ELP3 family. The elongator complex was originally thought to play a role in transcription elongation. However, it is no longer thought to play a direct role in this process and its primary function is thought to be in tRNA modification. The relevance of the protein lysine acetyltransferase activity is unclear (PubMed:29415125). The publication reporting acetylation of GJA1 does not provide direct evidence of lysine acetyltransferase activity of ELP3 (By similarity). Aberrant splicing.