1y14
From Proteopedia
Crystal structure of yeast subcomplex of Rpb4 and Rpb7
Structural highlights
Function[RPB4_YEAST] 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. RPB4 is part of a subcomplex with RPB7 that binds to a pocket formed by RPB1, RPB2 and RPB6 at the base of the clamp element. The RBP4-RPB7 subcomplex seems to lock the clamp via RPB7 in the closed conformation thus preventing double stranded DNA to enter the active site cleft. The RPB4-RPB7 subcomplex binds single-stranded DNA and RNA. The RPB4-RPB7 subcomplex is necessary for promoter-directed transcription initiation but is not required for recruitment of Pol II to active preinitiation complexes and seems to be dispensable for transcription elongation and termination. The RPB4-RPB7 subcomplex recruits FCP1 to Pol II. Involved in DNA repair of damage in the transcribed strand. RPB4 is dispensable under optimal growth conditions, but becomes essential during heat or cold shock and under nutrient depletion. Suppresses the RBP9-mediated transcription-coupled repair (TCR) subpathway of nucleotide excision repair (NER) but facilitates the RAD26-mediated TCR subpathway. Under stress conditions only, involved in mRNA export to the cytoplasm. Involved in mRNA decay. Promotes or enhances the deadenylation process of specific mRNAs and may recruit PAT1 and the LSM1-7 complex to these mRNAs, thus stimulating their decapping and further decay.[1] [2] [3] [4] [5] [6] [7] [RPB7_YEAST] 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. RPB7 is part of a subcomplex with RPB4 that binds to a pocket formed by RPB1, RPB2 and RPB6 at the base of the clamp element. The RBP4-RPB7 subcomplex seems to lock the clamp via RPB7 in the closed conformation thus preventing double stranded DNA to enter the active site cleft. The RPB4-RPB7 subcomplex binds single-stranded DNA and RNA. The RPB4-RPB7 subcomplex recruits FCP1 to Pol II.[8] [9] [10] 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 PubMedWe determined the x-ray structure of the RNA polymerase (Pol) II subcomplex Rpb4/7 at 2.3 A resolution, combined it with a previous structure of the 10-subunit polymerase core, and refined an atomic model of the complete 12-subunit Pol II at 3.8-A resolution. Comparison of the complete Pol II structure with structures of the Pol II core and free Rpb4/7 shows that the core-Rpb4/7 interaction goes along with formation of an alpha-helix in the linker region of the largest Pol II subunit and with folding of the conserved Rpb7 tip loop. Details of the core-Rpb4/7 interface explain facilitated Rpb4/7 dissociation in a temperature-sensitive Pol II mutant and specific assembly of Pol I with its Rpb4/7 counterpart, A43/14. The refined atomic model of Pol II serves as the new reference structure for analysis of the transcription mechanism and enables structure solution of complexes of the complete enzyme with additional factors and nucleic acids by molecular replacement. Structures of complete RNA polymerase II and its subcomplex, Rpb4/7.,Armache KJ, Mitterweger S, Meinhart A, Cramer P J Biol Chem. 2005 Feb 25;280(8):7131-4. Epub 2004 Dec 9. PMID:15591044[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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