Thursday September 24 2009
CEA
Characterization of the Synechocystis Strain PCC 6803 Penicillin-Binding Proteins and Cytokinetic Proteins FtsQ and FtsW and Their Network of Interactions with ZipN.
J. Bacteriol. (2009) 191: 5123-5133
CEA
Because very little is known about cell division in noncylindricalbacteria and cyanobacteria, we investigated 10 putative cytokineticproteins in the unicellular spherical cyanobacterium Synechocystisstrain PCC 6803. Concerning the eight penicillin-binding proteins(PBPs), which define three classes, we found that Synechocystiscan survive in the absence of one but not two PBPs of eitherclass A or class C, whereas the unique class B PBP (also termedFtsI) is indispensable. Furthermore, we showed that all threeclasses of PBPs are required for normal cell size. Similarly,the putative FtsQ and FtsW proteins appeared to be requiredfor viability and normal cell size. We also used a suitablebacterial two-hybrid system to characterize the interactionweb among the eight PBPs, FtsQ, and FtsW, as well as ZipN, thecrucial FtsZ partner that occurs only in cyanobacteria and plantchloroplasts. We showed that FtsI, FtsQ, and ZipN are self-interactingproteins and that both FtsI and FtsQ interact with class A PBPs,as well as with ZipN. Collectively, these findings indicatethat ZipN, in interacting with FtsZ and both FtsI and FtQ, playsa similar role to the Escherichia coli FtsA protein, which ismissing in cyanobacteria and chloroplasts.
Marbouty M, Mazouni K, Saguez C, Cassier-Chauvat C, Chauvat F. 2009. Characterization of the Synechocystis PCC6803 penicillin-binding proteins and cytokinetic proteins FtsQ and FtsW, and their network of interactions with ZipN. J. Bacteriol. 191: 5123-5133.