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Macrodomain organization of the Escherichia coli chromosome
Author(s) -
Valens Michèle,
Penaud Stéphanie,
Rossignol Michèle,
Cornet François,
Boccard Frédéric
Publication year - 2004
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600434
Subject(s) - biology , genetics , chromosome segregation , chromosome , sister chromatids , homologous recombination , dna , recombination , holliday junction , evolutionary biology , chromatid , gene
We have explored the Escherichia coli chromosome architecture by genetic dissection, using a site‐specific recombination system that reveals the spatial proximity of distant DNA sites and records interactions. By analysing the percentages of recombination between pairs of sites scattered over the chromosome, we observed that DNA interactions were restricted to within subregions of the chromosome. The results indicated an organization into a ring composed of four macrodomains and two less‐structured regions. Two of the macrodomains defined by recombination efficiency are similar to the Ter and Ori macrodomains observed by FISH. Two newly characterized macrodomains flank the Ter macrodomain and two less‐structured regions flank the Ori macrodomain. Also the interactions between sister chromatids are rare, suggesting that chromosome segregation quickly follows replication. These results reveal structural features that may be important for chromosome dynamics during the cell cycle.