The transpeptidase PBP2 governs initial localization and activity of the major cell-wall synthesis machinery in E. coli
Abstract
Bacterial shape is physically determined by the peptidoglycan cell wall. The cell-wall-synthesis machinery responsible for rod shape in Escherichia coli is the processive 'Rod complex'. Previously, cytoplasmic MreB filaments were thought to govern formation and localization of Rod complexes based on local cell-envelope curvature. Using single-particle tracking of the transpeptidase and Rod-complex component PBP2, we found that PBP2 binds to a substrate different from MreB. Depletion and localization experiments of other putative Rod-complex components provide evidence that none of those provide the sole rate-limiting substrate for PBP2 binding. Consistently, we found only weak correlations between MreB and envelope curvature in the cylindrical part of cells. Residual correlations do not require curvature-based Rod-complex initiation but can be attributed to persistent rotational motion. We therefore speculate that the local cell-wall architecture provides the cue for Rod-complex initiation, either through direct binding by PBP2 or through an unknown intermediate.
Data availability
All data generated or analysed during this study are included in supplemental datasets provided for each figure. Source data, specifically raw tracks, are provided as Source Data File (one file with x-, y- coordinates and track identifier per replicate).
Article and author information
Author details
Funding
H2020 European Research Council (679980)
- Sven van Teeffelen
Agence Nationale de la Recherche (ANR-10-LABX-62-IBEID)
- Sven van Teeffelen
Volkswagen Foundation
- Sven van Teeffelen
Mairie de Paris
- Sven van Teeffelen
Prestige Postdoctoral Fellowship
- Eva Wollrab
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Özbaykal et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.