{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T01:50:29Z","timestamp":1775785829437,"version":"3.50.1"},"reference-count":31,"publisher":"Oxford University Press (OUP)","issue":"1","license":[{"start":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T00:00:00Z","timestamp":1767916800000},"content-version":"vor","delay-in-days":4,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council","doi-asserted-by":"publisher","award":["2020\/GNT2000934"],"award-info":[{"award-number":["2020\/GNT2000934"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000923","name":"Australian Research Council","doi-asserted-by":"publisher","award":["IC200100052"],"award-info":[{"award-number":["IC200100052"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001843","name":"Science and Engineering Research Board","doi-asserted-by":"publisher","award":["CRG\/2020\/002622"],"award-info":[{"award-number":["CRG\/2020\/002622"]}],"id":[{"id":"10.13039\/501100001843","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,1,5]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Non-homologous end joining (NHEJ) is the sole pathway for repairing double-strand breaks in Mycobacterium tuberculosis during dormancy, relying on mycobacterial Ku (mKu) and ligase D, with mKu as the rate-limiting factor. Despite its essential role, the lack of structural information on prokaryotic Ku has hindered understanding of the molecular mechanisms underlying bacterial two-component NHEJ machinery. Here, we present the first cryo-electron microscopy (cryo-EM) structures of mKu in DNA-bound and higher-order supercomplex forms, revealing a Ku-mediated DNA synapsis mechanism unique to prokaryotes. Integrating cryo-EM with hydrogen\u2013deuterium exchange mass spectrometry, we define key mKu\u2013mKu dimerization, DNA-binding, and synapsis interactions essential for efficient NHEJ, bridging structure with function. Structure-guided in silico mutagenesis, coupled with electrophoretic mobility shift assays, identifies residues essential for DNA binding and synaptic assembly, which are crucial for NHEJ. F\u00f6rster resonance energy transfer confirms DNA-dependent mKu oligomerization in solution, while live-cell imaging captures its spatiotemporal dynamics during double-stranded DNA break repair. These findings provide fundamental insights into the architecture and function of prokaryotic NHEJ, positioning mKu as a potential therapeutic target against tuberculosis and offering a framework for understanding DNA repair across bacterial species.<\/jats:p>","DOI":"10.1093\/nar\/gkaf1418","type":"journal-article","created":{"date-parts":[[2025,11,30]],"date-time":"2025-11-30T12:44:32Z","timestamp":1764506672000},"source":"Crossref","is-referenced-by-count":1,"title":["Bringing the ends together: cryo-EM structures of mycobacterial Ku in complex with DNA define its role in NHEJ synapsis"],"prefix":"10.1093","volume":"54","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3633-7823","authenticated-orcid":false,"given":"Joydeep","family":"Baral","sequence":"first","affiliation":[{"name":"Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur , West Midnapore 721302, West Bengal ,","place":["India"]},{"name":"School of Physics, University of Melbourne , Victoria 3010 ,","place":["Australia"]},{"name":"Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria 3010 ,","place":["Australia"]},{"name":"Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins , Parkville, Victoria 3052 ,","place":["Australia"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ching-Seng","family":"Ang","sequence":"additional","affiliation":[{"name":"Melbourne Mass Spectrometry and Proteomics Facility, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Parkville, Victoria 3052 ,","place":["Australia"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paul James","family":"McMillan","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria 3010 ,","place":["Australia"]},{"name":"Biological Optical Microscopy Platform, University of Melbourne , Victoria 3010 ,","place":["Australia"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kalyan","family":"Shobhana","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria 3010 ,","place":["Australia"]},{"name":"Biological Optical Microscopy Platform, University of Melbourne , Victoria 3010 ,","place":["Australia"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ayushi","family":"Saini","sequence":"additional","affiliation":[{"name":"Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur , West Midnapore 721302, West Bengal ,","place":["India"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8317-1152","authenticated-orcid":false,"given":"Elizabeth","family":"Hinde","sequence":"additional","affiliation":[{"name":"School of Physics, University of Melbourne , Victoria 3010 ,","place":["Australia"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9703-1898","authenticated-orcid":false,"given":"Amit Kumar","family":"Das","sequence":"additional","affiliation":[{"name":"Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur , West Midnapore 721302, West Bengal ,","place":["India"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1288-8575","authenticated-orcid":false,"given":"Isabelle","family":"Rouiller","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology 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