module: dmel_n_terminal_acetyltransferase_complexes
title: N-terminal acetyltransferase complexes in Drosophila melanogaster
label: N-terminal acetyltransferase complexes
module_type: PROTEIN_COMPLEX
description: >-
  N-terminal acetyltransferases (NATs) transfer an acetyl group from acetyl-CoA
  to the alpha-amino group of protein N termini, mostly co-translationally at the
  ribosome. Each complex pairs a catalytic subunit with one or more auxiliary
  subunits that anchor it to the ribosome and shape substrate choice. NatA
  (catalytic Naa10, vnc in flies, with auxiliary Naa15-16) acetylates N termini
  exposed after removal of the initiator methionine; Naa50 (san) associates with
  NatA. NatB (Naa20 with Naa25, psidin) acetylates Met-Asp/Glu/Asn/Gln N termini.
  NatC (Naa30 with Naa35 and Naa38) acetylates Met followed by a hydrophobic
  residue. Drosophila has a testis-specific NatC catalytic paralog, Naa30B.
summary: >-
  NatA, NatB and NatC ribosome-associated N-terminal acetyltransferase complexes,
  including a testis-specific NatC variant.
concepts:
  - {id: GO:0031415, label: NatA complex}
  - {id: GO:0031416, label: NatB complex}
  - {id: GO:0031417, label: NatC complex}
parts:
  - id: nata
    label: NatA complex
    role: N-terminal acetylation after methionine removal
    group: NATA
    complex_term: {id: GO:0031415, label: NatA complex}
    unit_functions:
      vnc: {id: GO:0004596, label: protein-N-terminal amino-acid acetyltransferase activity}
    roles:
      vnc: catalytic subunit (Naa10)
      Naa15-16: auxiliary ribosome-anchoring subunit
      san: associated acetyltransferase (Naa50)
    processes:
      - {id: GO:0006474, label: N-terminal protein amino acid acetylation}
  - id: natb
    label: NatB complex
    role: acetylation of Met-acidic/amide N termini
    group: NATB
    complex_term: {id: GO:0031416, label: NatB complex}
    unit_functions:
      Naa20A: {id: GO:0004596, label: protein-N-terminal amino-acid acetyltransferase activity}
    roles:
      Naa20A: catalytic subunit (Naa20)
      psidin: auxiliary subunit (Naa25)
    processes:
      - {id: GO:0006474, label: N-terminal protein amino acid acetylation}
  - id: natc
    label: NatC complexes
    role: acetylation of Met-hydrophobic N termini
    variant_sets:
      - id: natc_variants
        label: Somatic or testis-specific NatC
        selection: ONE_OR_MORE
        variants:
          - id: natc_somatic
            label: NatC with Naa30A
            group: NATC
            complex_term: {id: GO:0031417, label: NatC complex}
            unit_functions:
              Naa30A: {id: GO:0004596, label: protein-N-terminal amino-acid acetyltransferase activity}
            processes:
              - {id: GO:0006474, label: N-terminal protein amino acid acetylation}
          - id: natc_testis
            label: Testis-specific NatC with Naa30B
            group: NATC-T
            complex_term: {id: GO:0031417, label: NatC complex}
            unit_functions:
              Naa30B: {id: GO:0004596, label: protein-N-terminal amino-acid acetyltransferase activity}
            processes:
              - {id: GO:0006474, label: N-terminal protein amino acid acetylation}
notes: >-
  Parts follow FlyBase subgroups NATA, NATB, NATC and NATC-T. Catalytic activity
  is assigned to the Naa10, Naa20 and Naa30 orthologs by conservation with yeast
  and human NATs; no activity is assigned to san (Naa50), whose own substrate
  specificity in flies is not settled here, or to auxiliary subunits. Other NATs
  that act alone (NatD/Naa40, NatF/Naa60, NatH/Naa80) are not in these FlyBase
  groups. Naa20B is not a FlyBase member of NATB and is not included.