W0246

Protein Expression, Purification, and Crystallization of the Nuclear Receptor PPARg / SRC-1 Co-activator Complex. G. Bruce Wisely, Ann B. Miller, Robert T. Nolte, and Michael V. Milburn, Department of Structural Chemistry, GlaxoWellcome Research Institute, Research Triangle Park, North Carolina 27709, USA

An 88 amino acid fragment from the human steroid receptor co-activator (SRC-1), that is able to potentiate the transcriptional activity of several nuclear receptors, has been co-expressed, purified, and crystallized as a ternary complex with the ligand binding domain of human peroxisomal proliferator-activator receptor (PPARg) and a thiazolidinedione ligand BRL49653. PPARg is a member of the nuclear receptor family of transcriptional factors which includes the receptors for estrogen, retinoids, progesterone, thyroid and glucocorticoid. Nuclear receptors contain two domains of transactivation function (AF). Ligand independent AF-1 is in the N-terminal region of the receptor and ligand dependent AF-2 is in the ligand binding domain (1). Upon binding of the ligand, a conformational change occurs within the ligand binding domain, recruiting a pre-initiation complex to stimulate transcription (2). Mutations in the AF-2 helix abolish the transcriptional activity of the receptor which might be a result of disr

[1] P. Willy and D. Mangelsdorf, (1998) Hormones and Signaling, Vol.1, 307.

[2] E. Kalkhoven, et al. (1998) EMBO Journal 17(1), 232.

[3] D. Heery et al. (1997) Nature, 387, 733.