module: dmel_cytoplasmic_ribosome
title: Cytoplasmic (80S) ribosome in Drosophila melanogaster
label: Cytoplasmic ribosome
module_type: PROTEIN_COMPLEX
description: >-
  The cytoplasmic 80S ribosome translates nuclear-encoded mRNAs. It consists of
  a 40S small subunit, which binds mRNA and decodes it, and a 60S large subunit,
  which carries the peptidyl transferase centre and the polypeptide exit tunnel.
  Each subunit is built from ribosomal RNAs and dozens of ribosomal proteins
  named by the universal (u) and eukaryote-specific (e) nomenclature. In
  Drosophila several ribosomal proteins are encoded by duplicated genes, and
  some paralogs are expressed mainly in the germline or testis (for example
  RpL22-like). FlyBase therefore also defines testis-specific variant
  compositions of both subunits, in which RpS28-like, RpL22-like and RpL37-2
  appear only in the testis variants.
summary: >-
  40S and 60S cytoplasmic ribosomal subunits, with canonical and testis-specific
  paralog compositions.
concepts:
  - {id: GO:0022626, label: cytosolic ribosome}
parts:
  - id: small_subunit
    label: Cytoplasmic small (40S) ribosomal subunit
    role: mRNA decoding subunit
    variant_sets:
      - id: small_subunit_variants
        label: Canonical or testis-specific 40S composition
        selection: ONE_OR_MORE
        variants:
          - id: small_subunit_canonical
            label: Canonical 40S subunit
            group: RPS
            complex_term: {id: GO:0022627, label: cytosolic small ribosomal subunit}
            function: {id: GO:0003735, label: structural constituent of ribosome}
            processes:
              - {id: GO:0002181, label: cytoplasmic translation}
          - id: small_subunit_testis
            label: Testis-specific 40S subunit variant
            description: >-
              FlyBase testis variant composition, with RpS28-like in place of
              RpS28b and lacking the RpS10b and RpS19a paralogs.
            group: RPS-T
            complex_term: {id: GO:0022627, label: cytosolic small ribosomal subunit}
            function: {id: GO:0003735, label: structural constituent of ribosome}
            processes:
              - {id: GO:0002181, label: cytoplasmic translation}
  - id: large_subunit
    label: Cytoplasmic large (60S) ribosomal subunit
    role: peptidyl transferase subunit
    variant_sets:
      - id: large_subunit_variants
        label: Canonical or testis-specific 60S composition
        selection: ONE_OR_MORE
        variants:
          - id: large_subunit_canonical
            label: Canonical 60S subunit
            group: RPL
            complex_term: {id: GO:0022625, label: cytosolic large ribosomal subunit}
            function: {id: GO:0003735, label: structural constituent of ribosome}
            processes:
              - {id: GO:0002181, label: cytoplasmic translation}
          - id: large_subunit_testis
            label: Testis-specific 60S subunit variant
            description: >-
              FlyBase testis variant composition, with RpL22-like and RpL37-2 in
              place of RpL22 and RpL37-1 and lacking RpL10Ab.
            group: RPL-T
            complex_term: {id: GO:0022625, label: cytosolic large ribosomal subunit}
            function: {id: GO:0003735, label: structural constituent of ribosome}
            processes:
              - {id: GO:0002181, label: cytoplasmic translation}
notes: >-
  The subunit parts follow the four FlyBase subgroups (RPS, RPL and their
  testis-specific variants); most proteins are shared and appear in both the
  canonical and the testis variant of a subunit. The variant groups record
  composition as curated by FlyBase; whether every listed paralog swap occurs in
  a single ribosome population in vivo is not established. FlyBase lists
  ribosomal proteins only, so rRNAs are not participants here, and some members
  (RpL24-like, a RLP24 ribosome biogenesis homolog; Rack1) are associated
  proteins rather than core rRNA-binding proteins. Ribosome biogenesis factors,
  translation factors and mitochondrial ribosomes are separate modules.