7Q5B

Cryo-EM structure of Ty3 retrotransposon targeting a TFIIIB-bound tRNA gene

Summary for 7Q5B

• Entry DOI: 10.2210/pdb7q5b/pdb
• EMDB information: 13831
• Descriptor: DNA (56-MER), DNA (31-MER), DNA (34-MER), ... (9 entities in total)
• Functional Keywords: transcription, rna pol iii, ty3 retrotransposon, intasome, dna binding protein
• Biological source: Saccharomyces cerevisiae S288C; More
• Total number of polymer chains: 13
• Total formula weight: 927779.25

Authors

Abascal-Palacios, G.,Jochem, L.,Pla-Prats, C.,Beuron, F.,Vannini, A. (deposition date: 2021-11-03, release date: 2022-01-26, Last modification date: 2024-11-13)

Primary citation

Abascal-Palacios, G.,Jochem, L.,Pla-Prats, C.,Beuron, F.,Vannini, A.
Structural basis of Ty3 retrotransposon integration at RNA Polymerase III-transcribed genes.
Nat Commun, 12:6992-6992, 2021

PubMed Abstract: Retrotransposons are endogenous elements that have the ability to mobilise their DNA between different locations in the host genome. The Ty3 retrotransposon integrates with an exquisite specificity in a narrow window upstream of RNA Polymerase (Pol) III-transcribed genes, representing a paradigm for harmless targeted integration. Here we present the cryo-EM reconstruction at 4.0 Å of an active Ty3 strand transfer complex bound to TFIIIB transcription factor and a tRNA gene. The structure unravels the molecular mechanisms underlying Ty3 targeting specificity at Pol III-transcribed genes and sheds light into the architecture of retrotransposon machinery during integration. Ty3 intasome contacts a region of TBP, a subunit of TFIIIB, which is blocked by NC2 transcription regulator in RNA Pol II-transcribed genes. A newly-identified chromodomain on Ty3 integrase interacts with TFIIIB and the tRNA gene, defining with extreme precision the integration site position.

PubMed: 34848735
DOI: 10.1038/s41467-021-27338-w

Experimental method

ELECTRON MICROSCOPY (3.98 Å)