Trussart, Marie, 1985-Yus, EvaMartínez, SiraBaù, DavideTahara, Yuhei O.Pengo, ThomasWidjaja, MichaelKretschmer, SimonSwoger, JimDjordjevic, Steven P.Turnbull, LynneWhitchurch, Cynthia B.Miyata, MakotoMartí Renom, Marc A.Lluch-Senar, Maria 1982-Serrano Pubull, Luis, 1982-2018-06-262018-06-262017Trussart M, Yus E, Martinez S, Baù D, Tahara YO, Pengo T et al. Defined chromosome structure in the genome-reduced bacterium Mycoplasma pneumoniae. Nat Commun. 2017 Mar 8;8:14665. DOI: 10.1038/ncomms146652041-1723http://hdl.handle.net/10230/34968DNA-binding proteins are central regulators of chromosome organization; however, in genome-reduced bacteria their diversity is largely diminished. Whether the chromosomes of such bacteria adopt defined three-dimensional structures remains unexplored. Here we combine Hi-C and super-resolution microscopy to determine the structure of the Mycoplasma pneumoniae chromosome at a 10 kb resolution. We find a defined structure, with a global symmetry between two arms that connect opposite poles, one bearing the chromosomal Ori and the other the midpoint. Analysis of local structures at a 3 kb resolution indicates that the chromosome is organized into domains ranging from 15 to 33 kb. We provide evidence that genes within the same domain tend to be co-regulated, suggesting that chromosome organization influences transcriptional regulation, and that supercoiling regulates local organization. This study extends the current understanding of bacterial genome organization and demonstrates that a defined chromosomal structure is a universal feature of living systems.application/pdfeng© The Author(s) 2017. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/ncomms14665Chromosome structuresMycoplasma pneumoniaeMolecular modellingAlveolar rhabdomyosarcomaPneumoniainfo:eu-repo/semantics/openAccess