6exv
From Proteopedia
Structure of mammalian RNA polymerase II elongation complex inhibited by Alpha-amanitin
Structural highlights
Function[RPB9_PIG] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Component of RNA polymerase II which synthesizes mRNA precursors and many functional non-coding RNAs. Pol II is the central component of the basal RNA polymerase II transcription machinery. It is composed of mobile elements that move relative to each other. RPB9 is part of the upper jaw surrounding the central large cleft and thought to grab the incoming DNA template (By similarity). [I3LGP4_PIG] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[RuleBase:RU363031] [I3LCB2_PIG] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I, II and III which synthesize ribosomal RNA precursors, mRNA precursors and many functional non-coding RNAs, and small RNAs, such as 5S rRNA and tRNAs, respectively.[PIRNR:PIRNR000779] [I3LJR4_PIG] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.[RuleBase:RU004279] [AAMAT_AMAPH] Major toxin belonging to the bicyclic octapeptides amatoxins that acts by binding non-competitively to RNA polymerase II and greatly slowing the elongation of transcripts from target promoters (PubMed:4865716, PubMed:363352, PubMed:7642577, PubMed:8702941).[1] [2] [3] [4] [5] Publication Abstract from PubMedRNA polymerase II (Pol II) is the central enzyme that transcribes eukaryotic protein-coding genes to produce mRNA. The mushroom toxin alpha-amanitin binds Pol II and inhibits transcription at the step of RNA chain elongation. Pol II from yeast binds alpha-amanitin with micromolar affinity, whereas metazoan Pol II enzymes exhibit nanomolar affinities. Here, we present the high-resolution cryo-EM structure of alpha-amanitin bound to and inhibited by its natural target, the mammalian Pol II elongation complex. The structure revealed that the toxin is located in a pocket previously identified in yeast Pol II, but forms additional contacts with metazoan-specific residues, which explain why its affinity to mammalian Pol II is ~3000 times higher than for yeast Pol II. Our work provides the structural basis for the inhibition of mammalian Pol II by the natural toxin alpha-amanitin and highlights that cryo-EM is well suited to studying interactions of a small molecule with its macromolecular target. Cryo-EM structure of a mammalian RNA polymerase II elongation complex inhibited by alpha-amanitin.,Liu X, Farnung L, Wigge C, Cramer P J Biol Chem. 2018 Mar 17. pii: RA118.002545. doi: 10.1074/jbc.RA118.002545. PMID:29550768[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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