5n60

Cryo-EM structure of RNA polymerase I in complex with Rrn3 and Core Factor (Orientation I)

Loading... Status: waiting for Mol* initialization Structural highlights 5n60 is a 10 chain structure with sequence from Saccharomyces cerevisiae S288C. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 7.7Å Ligands: ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RPAC1_YEAST DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Common component of RNA polymerases I and III which synthesize ribosomal RNA precursors and small RNAs, such as 5S rRNA and tRNAs, respectively. RPAC1 is part of the Pol core element with the central large cleft and probably a clamp element that moves to open and close the cleft (By similarity). Publication Abstract from PubMed Transcription initiation at the ribosomal RNA promoter requires RNA polymerase (Pol) I and the initiation factors Rrn3 and core factor (CF). Here, we combine X-ray crystallography and cryo-electron microscopy (cryo-EM) to obtain a molecular model for basal Pol I initiation. The three-subunit CF binds upstream promoter DNA, docks to the Pol I-Rrn3 complex, and loads DNA into the expanded active center cleft of the polymerase. DNA unwinding between the Pol I protrusion and clamp domains enables cleft contraction, resulting in an active Pol I conformation and RNA synthesis. Comparison with the Pol II system suggests that promoter specificity relies on a distinct "bendability" and "meltability" of the promoter sequence that enables contacts between initiation factors, DNA, and polymerase. Structural Basis of RNA Polymerase I Transcription Initiation.,Engel C, Gubbey T, Neyer S, Sainsbury S, Oberthuer C, Baejen C, Bernecky C, Cramer P Cell. 2017 Mar 23;169(1):120-131.e22. doi: 10.1016/j.cell.2017.03.003. PMID:28340337 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also RNA polymerase 3D structures Transcription initiation factors 3D structures

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