3h0g
RNA Polymerase II from Schizosaccharomyces pombeRNA Polymerase II from Schizosaccharomyces pombe
Structural highlights
Function[RPB1_SCHPO] DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic component of RNA polymerase II which synthesizes mRNA precursors and many functional non-coding RNAs. Forms the polymerase active center together with the second largest subunit. 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. RPB1 is part of the core element with the central large cleft, the clamp element that moves to open and close the cleft and the jaws that are thought to grab the incoming DNA template. At the start of transcription, a single-stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol II. A bridging helix emanates from RPB1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol II by acting as a ratchet that moves the RNA-DNA hybrid through the active site by switching from straight to bent conformations at each step of nucleotide addition. During transcription elongation, Pol II moves on the template as the transcript elongates. Elongation is influenced by the phosphorylation status of the C-terminal domain (CTD) of Pol II largest subunit (RPB1), which serves as a platform for assembly of factors that regulate transcription initiation, elongation, termination and mRNA processing (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe second structure of a eukaryotic RNA polymerase II so far determined, that of the enzyme from the fission yeast Schizosaccharomyces pombe, is reported here. Comparison with the previous structure of the enzyme from the budding yeast Saccharomyces cerevisiae reveals differences in regions implicated in start site selection and transcription factor interaction. These aspects of the transcription mechanism differ between S. pombe and S. cerevisiae, but are conserved between S. pombe and humans. Amino acid changes apparently responsible for the structural differences are also conserved between S. pombe and humans, suggesting that the S. pombe structure may be a good surrogate for that of the human enzyme. Schizosacharomyces pombe RNA polymerase II at 3.6-A resolution.,Spahr H, Calero G, Bushnell DA, Kornberg RD Proc Natl Acad Sci U S A. 2009 Jun 9;106(23):9185-90. Epub 2009 May 20. PMID:19458260[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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