Details

Autor(en) / Beteiligte

• Wu, Xiao-Xian
• Mu, Wen-Hui
• Li, Fan
• Sun, Shu-Yi
• Cui, Chao-Jun
• Kim, Chanhong
• Zhou, Fei
• Zhang, Yu

Titel

Cryo-EM structures of the plant plastid-encoded RNA polymerase

Ist Teil von

• Cell, 2024-02, Vol.187 (5), p.1127-1144.e21

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2024

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Chloroplasts are green plastids in the cytoplasm of eukaryotic algae and plants responsible for photosynthesis. The plastid-encoded RNA polymerase (PEP) plays an essential role during chloroplast biogenesis from proplastids and functions as the predominant RNA polymerase in mature chloroplasts. The PEP-centered transcription apparatus comprises a bacterial-origin PEP core and more than a dozen eukaryotic-origin PEP-associated proteins (PAPs) encoded in the nucleus. Here, we determined the cryo-EM structures of Nicotiana tabacum (tobacco) PEP-PAP apoenzyme and PEP-PAP transcription elongation complexes at near-atomic resolutions. Our data show the PEP core adopts a typical fold as bacterial RNAP. Fifteen PAPs bind at the periphery of the PEP core, facilitate assembling the PEP-PAP supercomplex, protect the complex from oxidation damage, and likely couple gene transcription with RNA processing. Our results report the high-resolution architecture of the chloroplast transcription apparatus and provide the structural basis for the mechanistic and functional study of transcription regulation in chloroplasts. [Display omitted] •Plant chloroplast RNA polymerase comprises a catalytic core and four peripheral modules•The scaffold module stabilizes the catalytic core and bridges other modules•The protection module has SOD activity, and the RNA module recognizes RNA sequence•The regulation module likely controls transcription activity of the catalytic core The cryo-EM structures of Nicotiana tabacum (tobacco) chloroplast RNA polymerase apoenzyme and transcription elongation complexes reveal the composition, assembly, function, and evolution of the chloroplast transcription apparatus.