PMID:22432817

Citation	Chen, Y, Milam, SL and Erickson, HP (2012) SulA inhibits assembly of FtsZ by a simple sequestration mechanism. Biochemistry 51:3100-9
Abstract	We have investigated the inhibition by SulA of the assembly of Escherichia coli FtsZ. Using quantitative GTPase and fluorescence assays, we found that SulA inhibition resulted in an increase in the apparent critical concentration for FtsZ assembly. The increase in apparent critical concentration was always less than the total amount of SulA added, suggesting that the association of SulA and FtsZ was of modest affinity. Isothermal titration calorimetry gave a value of 0.78 μM for the dissociation constant of the FtsZ-SulA complex, similar in magnitude to the 0.72 μM critical concentration of FtsZ protofilament assembly at steady state. We modeled the reaction as an equilibrium competition between (a) FtsZ subunits assembling onto protofilaments or (b) binding SulA. When FtsZ was assembled in GMPCPP or in EDTA, the inhibition by SulA was reduced. The reduced inhibition could be explained by a 3- and 10-fold weaker binding of SulA to FtsZ. The mutant D212G, which has no GTPase activity and therefore minimal subunit cycling, was shown here to assemble one-stranded protofilaments, and the assembly was blocked by SulA. We also assayed the SulA and FtsZ proteins from Pseudomonas. The SulA inhibition was stronger than with the E. coli proteins, and the model indicated a 5-fold higher affinity of Pseudomonas SulA for FtsZ.
Links	PubMed Online version:10.1021/bi201669d
Keywords	Bacterial Proteins/antagonists & inhibitors; Bacterial Proteins/chemistry; Bacterial Proteins/metabolism; Binding Sites; Cytoskeletal Proteins/antagonists & inhibitors; Cytoskeletal Proteins/chemistry; Cytoskeletal Proteins/metabolism; Escherichia coli/chemistry; Escherichia coli/metabolism; Escherichia coli Proteins/chemistry; Escherichia coli Proteins/metabolism; GTP Phosphohydrolases/metabolism; Kinetics; Microscopy, Electron; Mutation; Pseudomonas aeruginosa/metabolism
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
ECOLX:SULA		GO:0032466: negative regulation of cytokinesis	ECO:0000315:		P		SulA inhibits the assembly of FtsZ, preventing the cells from performing cytokenesis. Figure 8E showing the increase in SulA,causes a decrease in FtsZ formation. Figure 6 EM images of PaFtsZ and the inhibition of assemble by SulA. Figure 1 (a,b) EM images of ECFtsZ without SulA and with the indicated addition of SulA	complete CACAO 4059

References

See Help:References for how to manage references in GONUTS.