Abstract

The divisome is a protein complex responsible for controlling bacterial cytokinesis during cell division.1 In this machinery, the FtsQBL complex plays an important role in regulating the septal peptidoglycan (sPG) synthesis that is essential for cell separation.2 Unfortunately, limited information is available regarding the structure and conformational dynamic due to the membrane-embedded nature. With the application of Hydrogen-deuterium Exchange Mass Spectrometry (HDX-MS), we are able to get an insight into the structural dynamics of each component in their free and complex state. FtsB contains limited structural features with a transmembrane helix, while the FtsL is a single helix that probably extends from the membrane section. The formation of the FtsBL complex would induce a periplasmic helix in FtsB. This rigid secondary structure also brings the constriction control domains (CCDs) together, which may be curial for regulating the divisome. The introduction of FtsQ induced a slight effect on the FtsBL complex. However, the interaction with FtsBL would make FtsQ significantly rigid at the β-domains and the region connecting α- and β-domains.

References:

1. Blaauwen, T. D., Hamoen, L. W., & Levin, P. A. Curr Opin Microbiol, 2017, 36, 85 – 94.
2. Boes, A., Olatunji, S., Breukink, E., & Terrak, M. MBio, 2019, 10, e01912 – 18.