Component 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:15769872, PubMed:18755837). The elongator complex catalyzes formation of carboxymethyluridine in the wobble base at position 34 in tRNAs (PubMed:29332244). It functions as a gamma-toxin target (TOT); disruption of the complex confers resistance to Kluyveromyces lactis toxin zymocin (pGKL1 killer toxin) (PubMed:11296232). May also be involved in sensitivity to Pichia inositovora toxin (PubMed:13680368). tRNA modification; 5-methoxycarbonylmethyl-2-thiouridine-tRNA biosynthesis. Component of the elongator complex which consists of ELP1/IKI3, ELP2, ELP3, ELP4, ELP5/IKI1 and ELP6 (PubMed:11435442, PubMed:11390369, PubMed:11689709, PubMed:27974378, PubMed:27872205). The elongator complex is composed of two copies of the Elp123 subcomplex (composed of ELP1/IKI3, ELP2 and ELP3) and two copies of the Elp456 subcomplex (composed of ELP4, ELP5/IKI1 and ELP6) (PubMed:27974378, PubMed:27872205). The Elp123 subcomplex forms a two-lobed scaffold, which binds the Elp456 subcomplex asymmetrically (PubMed:27974378, PubMed:27872205). In each lobe, ELP2 is tightly sandwiched between ELP1/IKI3 and ELP3 (PubMed:31309145). The Elp123 subcomplex binds tRNA through ELP1/IKI3 and ELP3 and can bind 2 tRNAs simultaneously (PubMed:31309145). tRNA-binding by the Elp123 subcomplex induces conformational rearrangements which precisely position the targeted anticodon base in the active site (PubMed:31309145). The Elp456 subcomplex binds tRNA and has ATPase activity (PubMed:22556426, PubMed:22343726). Belongs to the ELP6 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.