9N69
Structure of the retron IA complex with HNH nuclease in the "down" orientation
Summary for 9N69
| Entry DOI | 10.2210/pdb9n69/pdb |
| EMDB information | 49053 |
| Descriptor | AAA family ATPase, RNA-directed DNA polymerase, TIGR02646 family protein, ... (7 entities in total) |
| Functional Keywords | retron, ia, immune, transferase-dna-rna complex, transferase/dna/rna |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 8 |
| Total formula weight | 419945.12 |
| Authors | Burman, N.,Thomas-George, J.,Wilkinson, R.,Wiedenheft, B. (deposition date: 2025-02-05, release date: 2025-04-23) |
| Primary citation | George, J.T.,Burman, N.,Wilkinson, R.A.,de Silva, S.,McKelvey-Pham, Q.,Buyukyoruk, M.,Dale, A.,Landman, H.,Graham, A.,DeLuca, S.Z.,Wiedenheft, B. Structural basis of antiphage defense by an ATPase-associated reverse transcriptase. Biorxiv, 2025 Cited by PubMed Abstract: Reverse transcriptases (RTs) have well-established roles in the replication and spread of retroviruses and retrotransposons. However, recent evidence suggests that RTs have been conscripted by cells for diverse roles in antiviral defense. Here we determine structures of a type I-A retron, which explain how RNA, DNA, RT, HNH-nuclease and four molecules of an SMC-family ATPase assemble into a 364 kDa complex that provides phage defense. We show that phage-encoded nucleases trigger degradation of the retron-associated DNA, leading to disassembly of the retron and activation of the HNH nuclease. The HNH nuclease cleaves tRNA, stalling protein synthesis and arresting viral replication. Taken together, these data reveal diverse and paradoxical roles for RTs in the perpetuation and elimination of genetic parasites. PubMed: 40196496DOI: 10.1101/2025.03.26.645336 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.13 Å) |
Structure validation
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