Purity ~95% (SDS-PAGE). 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. Source: Recombinant protein corresponding to aa90-282 from human SIAH1, fused to His-tag at N-terminal expressed in E. coli. Molecular Weight: ~24.1kD(216aa) AA