Bacterial mitosis: partitioning protein ParA oscillates in spiral-shaped structures and positions plasmids at mid-cell
Article first published online: 19 MAR 2004
Volume 52, Issue 2, pages 385–398, April 2004
How to Cite
Ebersbach, G. and Gerdes, K. (2004), Bacterial mitosis: partitioning protein ParA oscillates in spiral-shaped structures and positions plasmids at mid-cell. Molecular Microbiology, 52: 385–398. doi: 10.1111/j.1365-2958.2004.04002.x
- Issue published online: 19 MAR 2004
- Article first published online: 19 MAR 2004
- Accepted 29 December, 2003.
The par2 locus of Escherichia coli plasmid pB171 encodes oscillating ATPase ParA, DNA binding protein ParB and two cis-acting DNA regions to which ParB binds (parC1 and parC2). Three independent techniques were used to investigate the subcellular localization of plasmids carrying par2. In cells with a single plasmid focus, the focus located preferentially at mid-cell. In cells with two foci, these located at quarter-cell positions. In the absence of ParB and parC1/parC2, ParA-GFP formed stationary helices extending from one end of the nucleoid to the other. In the presence of ParB and parC1/parC2, ParA-GFP oscillated in spiral-shaped structures. Amino acid substitutions in ParA simultaneously abolished ParA spiral formation, oscillation and either plasmid localization or plasmid separation at mid-cell. Therefore, our results suggest that ParA spirals position plasmids at the middle of the bacterial nucleoid and subsequently separate them into daughter cells.