Purity: > 95% by SDS - PAGE Format: Liquid. In 20 mM Tris-HCl buffer (pH 8.0) containing 1mMDTT, 0.1mM PMSF, 20% glycerol. Elongin B , also known as TCEB2, is a subunit of the transcription factor B (SIII) complex. The SIII complex is a heterotrimer consisting of a transcriptionally active subunit (A) and two regulatory subunits (B and C). It activates elongation by RNA polymerase II by suppressing transient pausing of the polymerase at many sites within transcription units. The von Hippel-Lindau tumor suppressor protein (pVHL) binds to elongins B and C, and thereby inhibits transcription elongation. Recombinant TCEB2 was expressed as insoluble protein aggregate in E.coli and purified by conventional chromatography, after refolding of the isolated inclusion bodies in a renaturation buffer.