Purity: > 90% by SDS - PAGE Format: Liquid. In 20mM Tris-HCl buffer (pH 8.0) containing 1mM DTT, 10% glycerol. Activating transcription factor 4, also known as ATF4, belongs to a family of DNA-binding proteins that includes the AP-1 family of transcription factors, cAMP-response element binding proteins and CREB-like proteins. ATF4 encodes a transcription factor that was originally identified as a widely expressed mammalian DNA binding protein that could bind a tax-responsive enhancer element in the LTR of HTLV-1. Recombinant human ATF4 protein, fused to His-Calmodulin tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.