The replicated ftsQAZ and minB chromosomal regions of Escherichia coli segregate on average in line with nucleoid movement.
The average cellular positions of the ftsQAZ region (2 min) and the minB region (26.5 min) during the cell cycle was determined by fluorescent in situ hybridization using the position of oriC as a reference point. At the steady-state growth conditions used, newborn cells had replicated about 50% of the chromosome. By measuring the distances of the labelled oriCs with respect to mid-cell, we found two well-separated average oriC positions in cells of newborn length. These average oriC positions moved further apart along with cell elongation. The cellular position of the ftsQAZ gene region resembled the position of oriC, although its average position was closer to mid-cell. In contrast, a single minB focus was observed at cell birth. Separated minB foci appeared towards the end of DNA replication. The average positions of oriC, ftsQAZ and minB relative to each other fitted a model in which DNA replication takes place in the cell centre and subsequent gene regions pass sequentially through this centre. We have interpreted the polarized orientation of the studied gene regions as a consequence of the mode of DNA segregation.
Roos
M
M
Swammerdam Institute for Life Sciences, BioCentrum Amsterdam, University of Amsterdam, Kruislaan 316, 1098 SM Amsterdam, The Netherlands.
van Geel
A B
AB
Aarsman
M E
ME
Veuskens
J T
JT
Woldringh
C L
CL
Nanninga
N
N
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics* / Q000502:physiology; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000502:physiology; D002876:Chromosomes, Bacterial / Q000502:physiology*; D003598:Cytoskeletal Proteins; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D029968:Escherichia coli Proteins; D017404:In Situ Hybridization, Fluorescence; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018741:Replication Origin / Q000235:genetics
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C065103:FtsA protein, Bacteria; C489310:FtsA protein, E coli; C068023:FtsQ protein, E coli; C071525:FtsZ protein, Bacteria; D008565:Membrane Proteins; C080466:MinC protein, Bacteria; C093548:MinE protein, E coli; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli