Architecture of the yeast Pol III pre-termination complex and pausing mechanism on poly(dT) termination signals

Girbig, Mathias, Xie, Juanjuan, Grötsch, Helga, Libri, Domenico, Porrua, Odil, Müller, Christoph W (September 2022) Architecture of the yeast Pol III pre-termination complex and pausing mechanism on poly(dT) termination signals. Cell Reports, 40 (10). p. 111316. ISSN 2211-1247

PDF 2022-Mueller-Architecture-of-the-yeast-Pol-III-pre-termination-complex-and-pausing-mechanism-on-poly(dt)-termination-signals.pdf Available under License Creative Commons Attribution. Download (6MB)

Abstract

RNA polymerase (Pol) III is specialized to transcribe short, abundant RNAs, for which it terminates transcription on polythymine (dT) stretches on the non-template (NT) strand. When Pol III reaches the termination signal, it pauses and forms the pre-termination complex (PTC). Here, we report cryoelectron microscopy (cryo-EM) structures of the yeast Pol III PTC and complementary functional states at resolutions of 2.7-3.9 Å. Pol III recognizes the poly(dT) termination signal with subunit C128 that forms a hydrogen-bond network with the NT strand and, thereby, induces pausing. Mutating key interacting residues interferes with transcription termination in vitro, impairs yeast growth, and causes global termination defects in vivo, confirming our structural results. Additional cryo-EM analysis reveals that C53-C37, a Pol III subcomplex and key termination factor, participates indirectly in Pol III termination. We propose a mechanistic model of Pol III transcription termination and rationalize why Pol III, unlike Pol I and Pol II, terminates on poly(dT) signals.

Item Type:	Paper
Subjects:	Investigative techniques and equipment > microscopy > Cryo-electron microscopy Investigative techniques and equipment bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > RNA polymerase organism description > yeast > Saccharomyces bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes Investigative techniques and equipment > microscopy organism description > yeast
CSHL Authors:	Xie, Juanjuan
Communities:	CSHL labs > Schorn lab
SWORD Depositor:	CSHL Elements
Depositing User:	CSHL Elements
Date:	6 September 2022
Date Deposited:	08 Nov 2022 20:41
Last Modified:	11 Jan 2024 20:20
URI:	https://repository.cshl.edu/id/eprint/40750

Actions (login required)

Administrator's edit/view item