UbcH2 is the human homolog to the yeast DNA repair gene RAD6, which is induced by DNA damaging reagents. It has been shown to conjugate ubiquitin to histone H2A in an E3 dependent manner in vitro. UbcH2 consists of two functionally independent domains, an N-terminal core domain with ubiquitin conjugating activity, and a C-terminal domain that interacts with substrate proteins. This protein is useful for in vitro ubiquitinylation reactions. The His-tagged version of this enzyme is not susceptible to self-ubiquitinylation, which can occur with GST-tagged versions. Typical enzyme concentration to support conjugation in
vitro is 100 nM to 1 uM depending upon conditions.