Structure of the multi-subunit chloroplast RNA polymerase

verfasst von

Paula F V do Prado, Frederik M Ahrens, Monique Liebers, Noah Ditz, Hans-Peter Braun, Thomas Pfannschmidt, Hauke Hillen

Abstract

Chloroplasts contain a dedicated genome that encodes subunits of the photosynthesis machinery. Transcription of photosynthesis genes is predominantly carried out by a plastid-encoded RNA polymerase (PEP), a nearly 1 MDa complex composed of core subunits with homology to eubacterial RNA polymerases (RNAPs) and at least 12 additional chloroplast-specific PEP-associated proteins (PAPs). However, the architecture of this complex and the functions of the PAPs remain unknown. Here, we report the cryo-EM structure of a 19-subunit PEP complex from Sinapis alba (white mustard). The structure reveals that the PEP core resembles prokaryotic and nuclear RNAPs but contains chloroplast-specific features that mediate interactions with the PAPs. The PAPs are unrelated to known transcription factors and arrange around the core in a unique fashion. Their structures suggest potential functions during transcription in the chemical environment of chloroplasts. These results reveal structural insights into chloroplast transcription and provide a framework for understanding photosynthesis gene expression.

Organisationseinheit(en)

Institut für Botanik
AG Pflanzenphysiologie
Institut für Pflanzengenetik
Abteilung Pflanzenmolekularbiologie und Pflanzenproteomik

Externe Organisation(en)

Georg-August-Universität Göttingen
Universitätsmedizin Göttingen (UMG)

Typ

Artikel

Journal

Molecular cell

Band

84

Seiten

910-925.e5

ISSN

1097-2765

Publikationsdatum

07.03.2024

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Molekularbiologie, Zellbiologie

Elektronische Version(en)

https://doi.org/10.1016/j.molcel.2024.02.003 (Zugang: Offen)