title: Multiple interactions between the transmembrane division proteins of Bacillus subtilis and the role of FtsL instability in divisome assembly.
abstract: About 11 essential proteins assemble into a ring structure at the surface of the cell to bring about cytokinesis in bacteria. Several of these proteins have their major domains located outside the membrane, forming an assembly that we call the outer ring (OR). Previous work on division in Bacillus subtilis has shown that four of the OR proteins-FtsL, DivIC, DivIB, and PBP 2B-are interdependent for assembly. This contrasts with the mainly linear pathway for the equivalent proteins in Escherichia coli. Here we show that the interdependent nature of the B. subtilis pathway could be due to effects on FtsL and DivIC stability and that DivIB is an important player in regulating this turnover. Two-hybrid approaches suggest that a multiplicity of protein-protein interactions contribute to the assembly of the OR. DivIC is unusual in interacting strongly only with FtsL. We propose a model for the formation of the OR through the mutual association of the membrane proteins directed by the cytosolic inner-ring proteins.
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, Sout Parks Road, Oxford OX1 3RE, United Kingdom. Richard.Daniel@ncl.ac.uk
authors.forename: Richard A
authors.initials: RA
authors.lastname: Daniel
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Noirot-Gros
authors.forename: Philippe
authors.initials: P
authors.lastname: Noirot
authors.forename: Jeff
authors.initials: J
authors.lastname: Errington
mesh_terms: D001412:Bacillus subtilis / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D008565:Membrane Proteins / Q000378:metabolism; D008853:Microscopy; D008954:Models, Biological; D016254:Mutagenesis, Insertional; D011485:Protein Binding; D020798:Two-Hybrid System Techniques
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; C085861:DivIB protein, Bacillus subtilis; C110609:DivIC protein, Bacillus subtilis; D008565:Membrane Proteins