Cloning, purification and preliminary X-ray data analysis of the human ID2 homodimer

Marie V. Wong, Paaventhan Palasingam, Prasanna Kolatkar

Research output: Contribution to journalArticle

2 Citations (Scopus)


The ID proteins are named for their role as inhibitors of DNA binding and differentiation. They contain a helix-loop-helix (HLH) domain but lack a basic DNA-binding domain. In complex with basic HLH (bHLH) transcription factors, gene expression is regulated by DNA-binding inactivation. Although the HLH domain is highly conserved and shares a similar topology, the IDs preferentially bind class I bHLH-group members such as E47 (TCF3) but not the class III bHLH member Myc. A structure of an ID protein could potentially shed light on its mechanism. Owing to their short half-lives in vivo and reported in vitro instability, this paper describes the strategies that went into expressing sufficient soluble and stable ID2 to finally obtain diffraction-quality crystals. A 2.1 Å resolution data set was collected from a crystal belonging to space group P3121 with unit-cell parameters a = b = 51.622, c = 111.474 Å, = Β = 90, = 120° that was obtained by hanging-drop vapour diffusion in a precipitant solution consisting of 0.1 M MES pH 6.5, 2.0 M potassium acetate. The solvent content was consistent with the presence of one or two molecules in the asymmetric unit.

Original languageEnglish
Pages (from-to)1354-1358
Number of pages5
JournalActa Crystallographica Section F: Structural Biology and Crystallization Communications
Issue number11
Publication statusPublished - 1 Nov 2012
Externally publishedYes



  • helix-loop-helix domain
  • homodimer
  • ID2
  • inhibitor of DNA binding

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Structural Biology
  • Genetics
  • Condensed Matter Physics

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