Purpose of this project was to understand molecular mechanism to regulate bacterial cell shape. Analyses of the suppressor mutants of the rodZ mutant suggested that RodZ regulates assembly of MreB filaments. This result was published in 2012. In order to analyze the importance of the positively-charged residues in the juxta-membrane domain, I introduced Alanine into the residues and deleted the domain. I found that the positively-charged residues is dispensable for the RodZ function while the length of the domain is critical. I also analyzes the interaction among proteins constituting supramolecular machinery, elongasome. I found that RodZ interacts with MreB, MreC, PBP2, and RodA and that there are two sub-complexes in the complex, that is, MreB/MreC and PBP2/RodA complexes. The results indicate that RodZ bridges the sub-complexes. I also applied site-specific in vivo photo crosslink assay to detect interaction between RodZ and other proteins. I could detect crosslinked products.