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

ABSTRACT: 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 P3(1)21 with unit-cell parameters a=b=51.622, c=111.474?Å, ?=?=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.

SUBMITTER: Wong MV 

PROVIDER: S-EPMC3515380 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature