Biomaterial Database

Studies on the inhibition by alpha-amanitin of single-step addition reactions and productive RNA synthesis catalysed by wheat-germ RNA polymerase II. 1989

L de Mercoyrol, and C Job, and D Job

Centre de Biochimie et de Biologie Moléculaire, Centre National de la Recherche Scientifique, Marseille, France.

The rate of formation of a single phosphodiester bond with UTP substrate, U-A primer, poly[d(A-T)] template and wheat-germ RNA polymerase II is greatly depressed in the presence of alpha-amanitin. Half-maximal inhibition occurs at 0.04 microgram/ml, in close agreement with published values for inhibition of productive RNA synthesis with class II RNA polymerases from higher-plant species. However, a sizeable proportion of U-A-U synthesis is resistant to inhibition by excess alpha-amanitin. In the additional presence of ATP, i.e. under experimental conditions permitting RNA chain elongation, the synthesis of poly[r(A-U)] is arrested after the formation of the first phosphodiester bond. The results support the contention that the main enzymic process disrupted by alpha-amanitin is the translocation step of the transcription complex along the DNA template.

UI	MeSH Term	Description	Entries
D010726	Phosphodiesterase Inhibitors	Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.	Phosphodiesterase Antagonists,Phosphodiesterase Inhibitor,Phosphoric Diester Hydrolase Inhibitors,Antiphosphodiesterases,Inhibitor, Phosphodiesterase
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D000241	Adenosine	A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.	Adenocard,Adenoscan
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
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
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
D014498	Uracil	One of four nucleotide bases in the nucleic acid RNA.
D014908	Triticum	A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.	Wheat,Durum Wheat,Triticum aestivum,Triticum durum,Triticum spelta,Triticum turgidum,Triticum turgidum subsp. durum,Triticum vulgare,Durum Wheats,Wheat, Durum