9GBV
E.coli gyrase holocomplex with chirally wrapped 217 bp DNA fragment
Summary for 9GBV
| Entry DOI | 10.2210/pdb9gbv/pdb |
| EMDB information | 51222 |
| Descriptor | DNA gyrase subunit A, DNA gyrase subunit B, Mu217 DNA (159-MER), ... (5 entities in total) |
| Functional Keywords | dna gyrase, type ii topoisomerase, supercoiling, dna crossover, isomerase |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 6 |
| Total formula weight | 509252.83 |
| Authors | Michalczyk, E.,Ghilarov, D. (deposition date: 2024-07-31, release date: 2024-08-21, Last modification date: 2026-09-09) |
| Primary citation | Michalczyk, E.,Pakosz-Stepien, Z.,Liston, J.D.,Gittins, O.,Pabis, M.,Heddle, J.G.,Ghilarov, D. Structural basis of chiral wrap and T-segment capture by Escherichia coli DNA gyrase. Proc.Natl.Acad.Sci.USA, 121:e2407398121-e2407398121, 2024 Cited by PubMed Abstract: Type II topoisomerase DNA gyrase transduces the energy of ATP hydrolysis into the negative supercoiling of DNA. The postulated catalytic mechanism involves stabilization of a chiral DNA loop followed by the passage of the T-segment through the temporarily cleaved G-segment resulting in sign inversion. The molecular basis for this is poorly understood as the chiral loop has never been directly observed. We have obtained high-resolution cryoEM structures of gyrase with chirally wrapped 217 bp DNA with and without the fluoroquinolone moxifloxacin (MFX). Each structure constrains a positively supercoiled figure-of-eight DNA loop stabilized by a GyrA β-pinwheel domain which has the structure of a flat disc. By comparing the catalytic site of the native drug-free and MFX-bound gyrase structures both of which contain a single metal ion, we demonstrate that the enzyme is observed in a native precatalytic state. Our data imply that T-segment trapping is not dependent on the dimerization of the ATPase domains which appears to only be possible after strand passage has taken place. PubMed: 39589884DOI: 10.1073/pnas.2407398121 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.32 Å) |
Structure validation
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