PMID:21321206
| Citation |
Cho, H, McManus, HR, Dove, SL and Bernhardt, TG (2011) Nucleoid occlusion factor SlmA is a DNA-activated FtsZ polymerization antagonist.Proc. Natl. Acad. Sci. U.S.A. 108:3773-8 |
|---|---|
| Abstract |
The tubulin-like FtsZ protein initiates assembly of the bacterial cytokinetic machinery by polymerizing into a ring structure, the Z ring, at the prospective site of division. To block Z-ring formation over the nucleoid and help coordinate cell division with chromosome segregation, Escherichia coli employs the nucleoid-associated division inhibitor, SlmA. Here, we investigate the mechanism by which SlmA regulates FtsZ assembly. We show that SlmA disassembles FtsZ polymers in vitro. In addition, using chromatin immunoprecipitation (ChIP), we identified 24 SlmA-binding sequences (SBSs) on the chromosome. Remarkably, SlmA binding to SBSs dramatically enhanced its ability to interfere with FtsZ polymerization, and ChIP studies indicate that SlmA regulates FtsZ assembly at these sites in vivo. Because of the dynamic and highly organized nature of the chromosome, coupling SlmA activation to specific DNA binding provides a mechanism for the precise spatiotemporal control of its anti-FtsZ activity within the cell. |
| Links |
PubMed Online version:10.1073/pnas.1018674108 |
| Keywords |
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| edit table |
Main Points of the Paper
- SlmA antagonizes FtsZ polymerization
- SlmA binding consensus sequence identified
- Two missense mutants are used
- SlmA(R73D) is impaired in FtsZ binding
- SlmA(T33A) is impaired in DNA binding
- DNA-bound SlmA activates FtsZ's GTPase activity
- Model for SlmA's spatial and temporal regulation of FtsZ is presented
Materials and Methods Used
- Plating assay
- Electrophoretic Mobility Shift Assay (EMSA)
- FtsZ Polymerization Assay
- Protein purification for FtsZ and SlmA
- SDS-PAGE
- Serial dilutions
- Fluorescence Microscopy
- Electron Microscopy
- GTPase Assay
- Chromatography
Phenotype Annotations
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| Species | Taxon ID | Strain | Gene (if known) | OMP | Phenotype | Details | Evidence | Notes |
|---|---|---|---|---|---|---|---|---|
|
Escherichia coli |
slmA |
|
Other |
missense mutation corresponding to T33A mutation in the protein |
Binding Assay |
Figure 2- EMSA | ||
|
Escherichia coli |
slmA |
|
Other |
missense mutation corresponding to T33A mutation in the protein |
Binding Assay |
Figure 2- EMSA | ||
|
Escherichia coli |
ftsZ |
absent GTPase activity |
Metabolic Activity |
FtsZ variant D212N |
Biochemical Assay |
Figure 4- GTPase activity assay | ||
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Notes
References
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