module: dmel_elba_boundary_complex
title: Elba early boundary factor complex in Drosophila melanogaster
label: Elba complex
module_type: PROTEIN_COMPLEX
description: >-
  Elba is a heterotrimeric chromatin boundary (insulator) factor active in the
  early embryo. It binds a specific DNA sequence in the Fab-7 boundary of the
  Bithorax complex and gives the boundary its early insulating activity. Elba1
  and Elba2 are BEN-domain DNA-binding proteins, and Elba3 bridges them; Elba3
  is expressed only in early embryos, which restricts the complex to that
  stage.
summary: >-
  Embryonic heterotrimeric insulator factor (Elba1, Elba2, Elba3) that binds
  the Fab-7 boundary.
concepts:
  - {id: GO:0005667, label: transcription regulator complex}
cellular_components:
  - {id: GO:0000785, label: chromatin}
group: ELBA
unit_functions:
  Elba3: {id: GO:0030674, label: protein-macromolecule adaptor activity}
complex_function:
  function: {id: GO:0043035, label: chromatin insulator sequence binding}
  role_description: >-
    Binds the CCAATAAG Elba site in the Fab-7 boundary as an
    Elba1-Elba2-Elba3 heterotrimer and confers early embryonic
    enhancer-blocking activity.
roles:
  Elba1: BEN-domain DNA-binding subunit
  Elba2: BEN-domain DNA-binding subunit
  Elba3: bridging subunit
notes: >-
  No GO cellular-component term exists for Elba or insulator complexes, so the
  module is grounded to transcription regulator complex. A three-subunit complex
  without further sub-structure; it is decomposed one part per subunit.
  Chromatin insulator sequence binding (GO:0043035; GOA IDA for Elba1 and
  Elba2) is recorded on a complex-level annoton with all three subunits as
  active units, because the Elba1, Elba2 and Elba3 gene reviews record that
  the BEN-domain subunits contribute to it as part of the heterotrimer. The
  bridging subunit Elba3 is also given protein-macromolecule adaptor activity
  (GO:0030674; GOA IDA), its core function in its gene review.