Biomaterial Database

alpha-Amanitin-resistant RNA polymerase II from carpophores of Amanita species accumulating amatoxins. 1980

B C Johnson, and J F Preston

DNA-dependent RNA polymerase activities have been partially purified from carpophores of the amanitin (amatoxin)-accumulating species Amanita hygroscopica and Amanita suballiacea and the non-accumulating species Amanita brunnescens and Amanita alliacea. RNA polymerase II activities purified by ion-exchange chromatography were characterized with respect to ionic strength, template, and divalent metal ion requirements and sensitivities to inhibition by alpha-amanitin. The Ki values of alpha-amanitin for RNA polymerase II activities were: 2.0 . 10(-3) M for A. hygroscopica; 3.3 . 10(-3) M for A. suballiacea; 9.8 . 10(-6) M for A. brunnescens; 10.0 . 10(-6) M for A. alliacea. Further purification with DNA affinity chromatography of activities from A. suballiacea and A. brunnescens did not alter the apparent dissociation constants of alpha-amanitin from either enzyme. The correlation between amanitin sensitivity of RNA polymerase II and the quantity of amatoxins found in carpophores suggests these peptides may play a role in regulating transcription of messenger RNA during carpophore development.

UI	MeSH Term	Description	Entries
D002846	Chromatography, Affinity	A chromatographic technique that utilizes the ability of biological molecules, often ANTIBODIES, to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Bioaffinity,Immunochromatography,Affinity Chromatography,Bioaffinity Chromatography
D002852	Chromatography, Ion Exchange	Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.	Chromatography, Ion-Exchange,Ion-Exchange Chromatography,Chromatographies, Ion Exchange,Chromatographies, Ion-Exchange,Ion Exchange Chromatographies,Ion Exchange Chromatography,Ion-Exchange Chromatographies
D000363	Agaricales	An extensive order of basidiomycetous fungi whose fruiting bodies are commonly called mushrooms.	Agaricaceae,Mushrooms,Agaricale,Mushroom
D000545	Amanita	A genus of fungi of the family Agaricaceae, order Agaricales; most species are poisonous.	Amanitas
D000546	Amanitins	Cyclic peptides extracted from carpophores of various mushroom species. They are potent inhibitors of RNA polymerases in most eukaryotic species, blocking the production of mRNA and protein synthesis. These peptides are important in the study of transcription. Alpha-amanitin is the main toxin from the species Amanitia phalloides, poisonous if ingested by humans or animals.	Amanitin
D012318	RNA Polymerase I	A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. The enzyme functions in the nucleolar structure and transcribes DNA into RNA. It has different requirements for cations and salts than RNA polymerase II and III and is not inhibited by alpha-amanitin.	DNA-Dependent RNA Polymerase I,RNA Polymerase A,DNA Dependent RNA Polymerase I,Polymerase A, RNA,Polymerase I, RNA
D012319	RNA Polymerase II	A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.	DNA-Dependent RNA Polymerase II,RNA Pol II,RNA Polymerase B,DNA Dependent RNA Polymerase II
D012321	DNA-Directed RNA Polymerases	Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).	DNA-Dependent RNA Polymerases,RNA Polymerases,Transcriptases,DNA-Directed RNA Polymerase,RNA Polymerase,Transcriptase,DNA Dependent RNA Polymerases,DNA Directed RNA Polymerase,DNA Directed RNA Polymerases,Polymerase, DNA-Directed RNA,Polymerase, RNA,Polymerases, DNA-Dependent RNA,Polymerases, DNA-Directed RNA,Polymerases, RNA,RNA Polymerase, DNA-Directed,RNA Polymerases, DNA-Dependent,RNA Polymerases, DNA-Directed