XPB is a target of the natural product triptolide

Triptolide is a structurally different diterpene triepoxide abandoned from a acceptable Chinese alleviative bulb with anti-inflammatory, immunosuppressive, contraceptive and antitumor activities.
Its atomic apparatus of action, however, has remained abundantly ambiguous to date. We address that triptolide covalently binds to animal XPB,a subunit of the archetype agency TFIIH, and inhibits its DNA-dependent ATPase activity, which leads to the inhibition of RNA polymerase II–mediated archetype and acceptable nucleotide abatement repair. The identification of XPB as the ambition of triptolide accounts for the majority of the accepted biological activities of triptolide.
These allegation aswell advance that triptolide can serve as a new atomic delving for belief archetype and, potentially, as a new blazon of anticancer abettor through inhibition of the ATPase action of XPB.