Premium
Unlinking chromosome catenanes in vivo by site‐specific recombination
Author(s) -
Grainge Ian,
Bregu Migena,
Vazquez Mariel,
Sivanathan Viknesh,
Ip Stephen CY,
Sherratt David J
Publication year - 2007
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.7601849
Subject(s) - biology , recombination , genetics , chromosome , catenane , evolutionary biology , gene , chemistry , organic chemistry , molecule
A challenge for chromosome segregation in all domains of life is the formation of catenated progeny chromosomes, which arise during replication as a consequence of the interwound strands of the DNA double helix. Topoisomerases play a key role in DNA unlinking both during and at the completion of replication. Here we report that chromosome unlinking can instead be accomplished by multiple rounds of site‐specific recombination. We show that step‐wise, site‐specific recombination by XerCD‐ dif or Cre‐ loxP can unlink bacterial chromosomes in vivo , in reactions that require KOPS‐guided DNA translocation by FtsK. Furthermore, we show that overexpression of a cytoplasmic FtsK derivative is sufficient to allow chromosome unlinking by XerCD‐ dif recombination when either subunit of TopoIV is inactivated. We conclude that FtsK acts in vivo to simplify chromosomal topology as Xer recombination interconverts monomeric and dimeric chromosomes.