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Fully efficient chromosome dimer resolution in Escherichia coli cells lacking the integral membrane domain of FtsK
Author(s) -
Dubarry Nelly,
Barre FrançoisXavier
Publication year - 2010
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/emboj.2009.381
Subject(s) - biology , transmembrane domain , dna , translocase , transmembrane protein , integral membrane protein , chromosome segregation , escherichia coli , chromosome , biophysics , microbiology and biotechnology , circular bacterial chromosome , membrane protein , biochemistry , membrane , dna replication , gene , chromosomal translocation , receptor
In bacteria, septum formation frequently initiates before the last steps of chromosome segregation. This is notably the case when chromosome dimers are formed by homologous recombination. Chromosome segregation then requires the activity of a double‐stranded DNA transporter anchored at the septum by an integral membrane domain, FtsK. It was proposed that the transmembrane segments of proteins of the FtsK family form pores across lipid bilayers for the transport of DNA. Here, we show that truncated Escherichia coli FtsK proteins lacking all of the FtsK transmembrane segments allow for the efficient resolution of chromosome dimers if they are connected to a septal targeting peptide through a sufficiently long linker. These results indicate that FtsK does not need to transport DNA through a pore formed by its integral membrane domain. We propose therefore that FtsK transports DNA before membrane fusion, at a time when there is still an opening in the constricted septum.