Purity: > 90% by SDS - PAGE Format: Liquid. In 20mM Tris-HCl buffer (pH 8.0) containing 2mM DTT, 30% glycerol, 2mM EDTA, 0.1M NaCl . Cyclin H, also known as CDK7, is a member of the cyclin-dependent protein kinase family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. Cyclin H forms a trimeric complex with cyclin H and MAT1, which functions as a CDK-activating kinase (CAK). Cyclin H is an essential component of the transcription factor TFIIH that is involved in transcription initiation and DNA repair. Recombinant human Cyclin H, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.