Distribution of the Escherichia coli structural maintenance of chromosomes (SMC)-like protein MukB in the cell.
Fluorescent polyclonal antibodies specific for MukB have been used to study its localization in Escherichia coli. In wild-type cells, the MukB protein appeared as a limited number of oblong shapes embracing the nucleoid. MukB remained associated with the nucleoid in the absence of DNA replication. The centre of gravity of the dispersed MukB signal initially localized near mid-cell, but moved to approximately quarter positions well before the termination of DNA replication and its subsequent reinitiation. Because MukB had been reported to bind to FtsZ and to its eukaryotic homologue tubulin in vitro, cells were co-labelled with MukB- and FtsZ-specific fluorophores. No co-localization of MukB with polymerized FtsZ (the FtsZ ring) was observed at any time during the cell cycle. A possible role for MukB in preventing premature FtsZ polymerization and in DNA folding that might assist DNA segregation is discussed.
den Blaauwen
T
T
Swammerdam Institute for Life Sciences, Kruislaan 316, 1098 SM Amsterdam, PO Box 194062, 1090 GB Amsterdam, The Netherlands. blaauwen@science.uva.nl
Lindqvist
A
A
Löwe
J
J
Nanninga
N
N
D000906:Antibodies; D001398:Aztreonam / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002453:Cell Cycle; D048429:Cell Size; D002868:Chromosomal Proteins, Non-Histone; D002876:Chromosomes, Bacterial / Q000502:physiology*; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D004261:DNA Replication; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000235:genetics*; D029968:Escherichia coli Proteins; D008856:Microscopy, Fluorescence; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction
D000906:Antibodies; D001426:Bacterial Proteins; D002868:Chromosomal Proteins, Non-Histone; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; C067035:MukB protein, E coli; D011993:Recombinant Fusion Proteins; D001398:Aztreonam