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Cryo-EM structure of the RNA Polymerase III-Maf1 complex
Structural highlights
FunctionRPC1_YEAST DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Forms the polymerase active center together with the second largest subunit. A single-stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol III. A bridging helix emanates from RPC1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol III 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 (By similarity). Publication Abstract from PubMedMaf1 is a conserved inhibitor of RNA polymerase III (Pol III) that influences phenotypes ranging from metabolic efficiency to lifespan. Here, we present a 3.3-A-resolution cryo-EM structure of yeast Maf1 bound to Pol III, establishing that Maf1 sequesters Pol III elements involved in transcription initiation and binds the mobile C34 winged helix 2 domain, sealing off the active site. The Maf1 binding site overlaps with that of TFIIIB in the preinitiation complex. Structural basis for RNA polymerase III transcription repression by Maf1.,Vorlander MK, Baudin F, Moir RD, Wetzel R, Hagen WJH, Willis IM, Muller CW Nat Struct Mol Biol. 2020 Feb 17. pii: 10.1038/s41594-020-0383-y. doi:, 10.1038/s41594-020-0383-y. PMID:32066962[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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