†Present address: Laboratoire de Recherches laitières et Génétique Appliquée, URLGA, INRA Centre de Jouy-en-Josas, 78352 Jouy-en-Josas cedex, France.
Isolation and characterization of topological specificity mutants of minD in Bacillus subtilis
Article first published online: 13 JAN 2002
Volume 42, Issue 5, pages 1211–1221, December 2001
How to Cite
Karoui, M. E. and Errington, J. (2001), Isolation and characterization of topological specificity mutants of minD in Bacillus subtilis. Molecular Microbiology, 42: 1211–1221. doi: 10.1046/j.1365-2958.2001.02710.x
- Issue published online: 13 JAN 2002
- Article first published online: 13 JAN 2002
- Accepted 11 September, 2001.
In rod-shaped bacteria such as Bacillus subtilis, division site selection is mediated by MinC and MinD, which together function as a division inhibitor. Topological specificity is imposed by DivIVA, which ensures that MinCD specifically inhibits division close to the cell poles, while allowing division at mid-cell. MinD plays a central role in this process, as it positions and activates MinC and is dependent on DivIVA for its own positioning at the poles. To investigate MinD activities further, we have constructed and analysed a collection of minD mutants. Mutations in the conserved ATPase motifs lead to an inactive protein, possibly unable to oligomerize, but which nevertheless retains some affinity for the cell membrane. Several mutations affecting the mid- to C-terminal parts of MinD led to a protein probably unable to interact with DivIVA, but that could still stimulate division inhibition by MinC. These findings suggest that the ATPase activity of MinD is necessary for all its functions (possibly in part by controlling the oligomerization state of the protein). The other mutations may identify a surface of MinD involved in its interactions with DivIVA and a possible mechanism for control of MinD by DivIVA.