8Q72
E. coli plasmid-borne JetABCD(E248A) core in a cleavage-competent state
Summary for 8Q72
| Entry DOI | 10.2210/pdb8q72/pdb |
| EMDB information | 18201 18208 18209 18211 |
| Descriptor | JetC, JetB, JetA, ... (6 entities in total) |
| Functional Keywords | smc complexes, dna loop extrusion, nuclease, bacterial immunity, defense system, topoisomerase, plamid restriction, mksbefg, wadjet, eptabcd, horizontal gene transfer, dna binding protein, dna kinking |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 16 |
| Total formula weight | 864769.16 |
| Authors | Roisne-Hamelin, F.,Li, Y.,Gruber, S. (deposition date: 2023-08-15, release date: 2024-01-31, Last modification date: 2024-03-20) |
| Primary citation | Roisne-Hamelin, F.,Liu, H.W.,Taschner, M.,Li, Y.,Gruber, S. Structural basis for plasmid restriction by SMC JET nuclease. Mol.Cell, 84:883-, 2024 Cited by PubMed Abstract: DNA loop-extruding SMC complexes play crucial roles in chromosome folding and DNA immunity. Prokaryotic SMC Wadjet (JET) complexes limit the spread of plasmids through DNA cleavage, yet the mechanisms for plasmid recognition are unresolved. We show that artificial DNA circularization renders linear DNA susceptible to JET nuclease cleavage. Unlike free DNA, JET cleaves immobilized plasmid DNA at a specific site, the plasmid-anchoring point, showing that the anchor hinders DNA extrusion but not DNA cleavage. Structures of plasmid-bound JetABC reveal two presumably stalled SMC motor units that are drastically rearranged from the resting state, together entrapping a U-shaped DNA segment, which is further converted to kinked V-shaped cleavage substrate by JetD nuclease binding. Our findings uncover mechanical bending of residual unextruded DNA as molecular signature for plasmid recognition and non-self DNA elimination. We moreover elucidate key elements of SMC loop extrusion, including the motor direction and the structure of a DNA-holding state. PubMed: 38309275DOI: 10.1016/j.molcel.2024.01.009 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4.17 Å) |
Structure validation
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