7OBB

Cryo-EM structure of human RNA Polymerase I Open Complex

Summary for 7OBB

• Entry DOI: 10.2210/pdb7obb/pdb
• EMDB information: 12797
• Descriptor: DNA-directed RNA polymerase I subunit RPA1, DNA-directed RNA polymerases I and III subunit RPAC2, DNA-directed RNA polymerases I, II, and III subunit RPABC4, ... (16 entities in total)
• Functional Keywords: rna polymerase i, human, rrna transcription, dna-dependent rna polymerase, pre-initiation, open complex, transcription
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 15
• Total formula weight: 629781.88

Authors

Misiaszek, A.D.,Girbig, M.,Mueller, C.W. (deposition date: 2021-04-21, release date: 2021-12-08, Last modification date: 2024-07-10)

Primary citation

Misiaszek, A.D.,Girbig, M.,Grotsch, H.,Baudin, F.,Murciano, B.,Lafita, A.,Muller, C.W.
Cryo-EM structures of human RNA polymerase I.
Nat.Struct.Mol.Biol., 28:997-1008, 2021

PubMed Abstract: RNA polymerase I (Pol I) specifically synthesizes ribosomal RNA. Pol I upregulation is linked to cancer, while mutations in the Pol I machinery lead to developmental disorders. Here we report the cryo-EM structure of elongating human Pol I at 2.7 Å resolution. In the exit tunnel, we observe a double-stranded RNA helix that may support Pol I processivity. Our structure confirms that human Pol I consists of 13 subunits with only one subunit forming the Pol I stalk. Additionally, the structure of human Pol I in complex with the initiation factor RRN3 at 3.1 Å resolution reveals stalk flipping upon RRN3 binding. We also observe an inactivated state of human Pol I bound to an open DNA scaffold at 3.3 Å resolution. Lastly, the high-resolution structure of human Pol I allows mapping of disease-related mutations that can aid understanding of disease etiology.

PubMed: 34887565
DOI: 10.1038/s41594-021-00693-4

Experimental method

ELECTRON MICROSCOPY (3.3 Å)