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-Structure paper
Title | The large bat Helitron DNA transposase forms a compact monomeric assembly that buries and protects its covalently bound 5'-transposon end. |
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Journal, issue, pages | Mol Cell, Vol. 81, Issue 20, Page 4271-44286.e4, Year 2021 |
Publish date | Oct 21, 2021 |
Authors | Dalibor Kosek / Ivana Grabundzija / Haotian Lei / Ilija Bilic / Huaibin Wang / Yukun Jin / Graham F Peaslee / Alison B Hickman / Fred Dyda / |
PubMed Abstract | Helitrons are widespread eukaryotic DNA transposons that have significantly contributed to genome variability and evolution, in part because of their distinctive, replicative rolling-circle ...Helitrons are widespread eukaryotic DNA transposons that have significantly contributed to genome variability and evolution, in part because of their distinctive, replicative rolling-circle mechanism, which often mobilizes adjacent genes. Although most eukaryotic transposases form oligomers and use RNase H-like domains to break and rejoin double-stranded DNA (dsDNA), Helitron transposases contain a single-stranded DNA (ssDNA)-specific HUH endonuclease domain. Here, we report the cryo-electron microscopy structure of a Helitron transposase bound to the 5'-transposon end, providing insight into its multidomain architecture and function. The monomeric transposase forms a tightly packed assembly that buries the covalently attached cleaved end, protecting it until the second end becomes available. The structure reveals unexpected architectural similarity to TraI, a bacterial relaxase that also catalyzes ssDNA movement. The HUH active site suggests how two juxtaposed tyrosines, a feature of many replication initiators that use HUH nucleases, couple the conformational shift of an α-helix to control strand cleavage and ligation reactions. |
External links | Mol Cell / PubMed:34403695 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.66 Å |
Structure data | EMDB-23271, PDB-7lcc: |
Chemicals | ChemComp-ZN: |
Source |
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Keywords | RECOMBINATION / Helitron / transposase / evolution / gene editing / gene capture / rolling circle / replication / nuclease / helicase / relaxase |