8BFN
E. coli Wadjet JetABC dimer of dimers
Summary for 8BFN
| Entry DOI | 10.2210/pdb8bfn/pdb |
| EMDB information | 15609 16020 |
| Descriptor | JetC, JetB, JetA, ... (4 entities in total) |
| Functional Keywords | smc complexes, bacterial immunity, defense system, dna loop extrusion, wadjet, jetabcd, dna cleavage, plasmid restriction, mksbefg, mobile genetic elements, horizontal gene transfer, eptabcd, mukbef, dna binding protein |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 10 |
| Total formula weight | 738743.99 |
| Authors | Roisne-Hamelin, F.,Beckert, B.,Myasnikov, A.,Li, Y.,Gruber, S. (deposition date: 2022-10-26, release date: 2022-12-14, Last modification date: 2024-07-24) |
| Primary citation | Liu, H.W.,Roisne-Hamelin, F.,Beckert, B.,Li, Y.,Myasnikov, A.,Gruber, S. DNA-measuring Wadjet SMC ATPases restrict smaller circular plasmids by DNA cleavage. Mol.Cell, 82:4727-4740.e6, 2022 Cited by PubMed Abstract: Structural maintenance of chromosome (SMC) complexes fold DNA by loop extrusion to support chromosome segregation and genome maintenance. Wadjet systems (JetABCD/MksBEFG/EptABCD) are derivative SMC complexes with roles in bacterial immunity against selfish DNA. Here, we show that JetABCD restricts circular plasmids with an upper size limit of about 100 kb, whereas a linear plasmid evades restriction. Purified JetABCD complexes cleave circular DNA molecules, regardless of the DNA helical topology; cleavage is DNA sequence nonspecific and depends on the SMC ATPase. A cryo-EM structure reveals a distinct JetABC dimer-of-dimers geometry, with the two SMC dimers facing in opposite direction-rather than the same as observed with MukBEF. We hypothesize that JetABCD is a DNA-shape-specific endonuclease and propose the "total extrusion model" for DNA cleavage exclusively when extrusion of an entire plasmid has been completed by a JetABCD complex. Total extrusion cannot be achieved on the larger chromosome, explaining how self-DNA may evade processing. PubMed: 36525956DOI: 10.1016/j.molcel.2022.11.015 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.52 Å) |
Structure validation
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