title: Specific inhibition of nuclear RNA polymerase II by alpha-amanitin.
abstract: alpha-Amanitin, a toxic substance from the mushroom Amanita phalloides, is a potent inhibitor of DNA-dependent RNA polymerase II (the nucleoplasmic form) from sea urchin, rat liver, and calf thymus. This compound exerts no effect on the activity of polymerase I (nucleolar form) or polymerase III (also nucleoplasmic). The inhibition is due to a specific interaction with polymerase II or with a complex of DNA and polymerase II.
mesh_terms: D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000201:enzymology*; D004247:DNA; D004447:Echinodermata; D004926:Escherichia coli / Q000201:enzymology; D008099:Liver / Q000166:cytology / Q000201:enzymology; D009183:Mycotoxins / Q000494:pharmacology*; D012316:RNA Nucleotidyltransferases / Q000037:antagonists & inhibitors*; D051381:Rats; D013950:Thymus Gland / Q000166:cytology / Q000201:enzymology
chemical_list: D009183:Mycotoxins; D004247:DNA; D012316:RNA Nucleotidyltransferases