9JM0

retron Ec86-effector fiber

Summary for 9JM0

• Entry DOI: 10.2210/pdb9jm0/pdb
• EMDB information: 61595
• Descriptor: Retron Ec86 reverse transcriptase, Retron Ec86 putative ribosyltransferase/DNA-binding protein, DNA (85-MER), ... (7 entities in total)
• Functional Keywords: reverse transcriptase, rna binding protein/dna/rna, rna binding protein-dna-rna complex
• Biological source: Escherichia coli; More
• Total number of polymer chains: 20
• Total formula weight: 522410.91

Authors

Wang, Y.J.,Guan, Z.Y.,Wang, C.,Zou, T.T. (deposition date: 2024-09-20, release date: 2024-12-18)

Primary citation

Wang, Y.,Wang, C.,Guan, Z.,Cao, J.,Xu, J.,Wang, S.,Cui, Y.,Wang, Q.,Chen, Y.,Yin, Y.,Zhang, D.,Liu, H.,Sun, M.,Jin, S.,Tao, P.,Zou, T.
DNA methylation activates retron Ec86 filaments for antiphage defense.
Cell Rep, 43:114857-114857, 2024

PubMed Abstract: Retrons are a class of multigene antiphage defense systems typically consisting of a retron reverse transcriptase, a non-coding RNA, and a cognate effector. Although triggers for several retron systems have been discovered recently, the complete mechanism by which these systems detect invading phages and mediate defense remains unclear. Here, we focus on the retron Ec86 defense system, elucidating its modes of activation and mechanisms of action. We identified a phage-encoded DNA cytosine methyltransferase (Dcm) as a trigger of the Ec86 system and demonstrated that Ec86 is activated upon multicopy single-stranded DNA (msDNA) methylation. We further elucidated the structure of a tripartite retron Ec86-effector filament assembly that is primed for activation by Dcm and capable of hydrolyzing nicotinamide adenine dinucleotide (NAD). These findings provide insights into the retron Ec86 defense mechanism and underscore an emerging theme of antiphage defense through supramolecular complex assemblies.

PubMed: 39395169
DOI: 10.1016/j.celrep.2024.114857

Experimental method

ELECTRON MICROSCOPY (2.7 Å)