module: dmel_elongator_complex
title: Elongator complex in Drosophila melanogaster
label: Elongator complex
module_type: PROTEIN_COMPLEX
description: >-
  Elongator is a conserved six-subunit complex that modifies uridines at the
  wobble position (U34) of tRNAs by adding a carboxymethyl group, the first
  step towards mcm5U and mcm5s2U, which are needed for efficient and accurate
  decoding. It is formed by two subcomplexes. Elp1, Elp2 and Elp3 form the core
  subcomplex; Elp3 is the catalytic subunit, a radical SAM enzyme with an
  acetyltransferase domain, and Elp1 is the scaffold. Elp4, Elp5 and Elp6 form a
  hetero-hexameric RecA-like ring (two copies of each) that binds tRNA and
  ATP. In Drosophila, Elp3 is required for larval development and neuronal
  function.
summary: >-
  Elp1-3 catalytic subcomplex and Elp4-6 ring that carboxymethylate tRNA wobble
  uridines.
concepts:
  - {id: GO:0033588, label: elongator holoenzyme complex}
parts:
  - id: elp123
    label: Elp1-Elp2-Elp3 core subcomplex
    role: catalytic core and scaffold
    genes: [Elp1, Elp2, Elp3]
    unit_functions:
      Elp3: {id: GO:0106261, label: tRNA uridine(34) acetyltransferase activity}
    roles:
      Elp1: scaffold subunit
      Elp2: WD40 subunit
      Elp3: catalytic subunit
    processes:
      - {id: GO:0002098, label: tRNA wobble uridine modification}
  - id: elp456
    label: Elp4-Elp5-Elp6 ring subcomplex
    role: tRNA-binding hexameric ring
    genes: [Elp4, Elp5, Elp6]
    processes:
      - {id: GO:0002098, label: tRNA wobble uridine modification}
notes: >-
  The split into Elp1-3 and Elp4-6 subcomplexes follows the conserved
  architecture defined in yeast and human; FlyBase groups all six subunits in
  ELP. Elongator was first described as an RNA polymerase II elongation factor,
  but its established direct activity is tRNA modification, so transcription
  elongation is not a process here.