Purity: > 95% by SDS - PAGE Format: Liquid. In 20mM Tris-HCl buffer (pH 8.0) containing 0.1M NaCl, 40% glycerol,1mM DTT. E3 ubiquitin-protein ligase SIAH1, also known as SIAH1, is a member of the seven in absentia homolog (SIAH) family. SIAH1 is a tumor suppressor protein that is expressed in intestinal epithelium and activated during apoptosis. SIAH1 contains an N-terminal RING-finger domain, which is required for proteolysis, and a cystein-rich C-terminal domain, which regulates oligomerization and SIAH binding to target proteins. SIAH1 is known to cause indirect degradation of beta-catenin through formation of a complex with Siah-interacting protein (SIP), Skp1 and Ebi. Recombinant human SIAH1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.