The FtsK gamma domain directs oriented DNA translocation by interacting with KOPS.
The bacterial septum-located DNA translocase FtsK coordinates circular chromosome segregation with cell division. Rapid translocation of DNA by FtsK is directed by 8-base-pair DNA motifs (KOPS), so that newly replicated termini are brought together at the developing septum, thereby facilitating completion of chromosome segregation. Translocase functions reside in three domains, alpha, beta and gamma. FtsKalphabeta are necessary and sufficient for ATP hydrolysis-dependent DNA translocation, which is modulated by FtsKgamma through its interaction with KOPS. By solving the FtsKgamma structure by NMR, we show that gamma is a winged-helix domain. NMR chemical shift mapping localizes the DNA-binding site on the gamma domain. Mutated proteins with substitutions in the FtsKgamma DNA-recognition helix are impaired in DNA binding and KOPS recognition, yet remain competent in DNA translocation and XerCD-dif site-specific recombination, which facilitates the late stages of chromosome segregation.
Sivanathan
Viknesh
V
Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
Allen
Mark D
MD
de Bekker
Charissa
C
Baker
Rachel
R
Arciszewska
Lidia K
LK
Freund
Stefan M
SM
Bycroft
Mark
M
Löwe
Jan
J
Sherratt
David J
DJ
D001483:Base Sequence; D001665:Binding Sites; D002876:Chromosomes, Bacterial / Q000378:metabolism; D004265:DNA Helicases / Q000737:chemistry* / Q000378:metabolism*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000201:enzymology
D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C096452:FtsK protein, E coli; D008565:Membrane Proteins; D004265:DNA Helicases