LytM factors affect the recruitment of autolysins to the cell division site in Caulobacter crescentus
Abstract
Most bacteria possess a peptidoglycan cell wall that determines their morphology and provides mechanical robustness during osmotic challenges. The biosynthesis of this structure is achieved by a large set of synthetic and lytic enzymes with varying substrate specificities. Although the biochemical functions of these proteins are conserved and well-investigated, the precise roles of individual factors and the regulatory mechanisms coordinating their activities in time and space remain incompletely understood. Here, we comprehensively analyze the autolytic machinery of the alphaproteobacterial model organism Caulobacter crescentus, with a specific focus on LytM-like endopeptidases, soluble lytic transglycosylases and amidases. Our data reveal a high degree of redundancy within each protein family but also specialized functions for individual family members under stress conditions. In addition, we identify two lytic transglycosylases and an amidase as new divisome components that are recruited to midcell at distinct stages of the cell cycle. The midcell localization of these proteins is affected by two LytM factors with degenerate catalytic domains, DipM and LdpF, which may serve as regulatory hubs coordinating the activities of multiple autolytic enzymes during cell constriction and fission respectively. These findings set the stage for in-depth studies of the molecular mechanisms that control peptidoglycan remodeling in C. crescentus.
Additional Information
© 2017 John Wiley & Sons Ltd. Issue online: 23 October 2017; Version of record online: 14 September 2017; Accepted manuscript online: 23 August 2017; Manuscript Accepted: 18 August 2017. We thank Stephanie Steede and Julia Rosum for excellent technical assistance, Patrick Viollier for providing plasmids and Erin Goley for sharing data on C. crescentus FtsEX before publication. Moreover, we are grateful to Daniela Kiekebusch and Muriel van Teeseling for critical reading of the manuscript. This work was funded by core support from Philipps-Universität Marburg (to MT), a Max Planck Fellowship from the Max Planck Society (to MT) and funds from the Howard Hughes Medical Institute (to GJJ). AIM acknowledges funding from the International Max Planck Research School for Environmental, Cellular and Molecular Microbiology (IMPRS-Mic). The authors have no conflicts of interest related to this work. Author contributions: MB, AZ, AM and KK performed all genetic and cell biological analyses. AIM contributed to the phenotypic characterization of mutant strains. AB and GJJ conducted the electron cryo-tomography studies. AZ, AM and MT designed the study. AM, MB and MT wrote the manuscript.Attached Files
Supplemental Material - mmi13775-sup-0001-SuppInfo01.pdf
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Additional details
- Eprint ID
- 80816
- DOI
- 10.1111/mmi.13775
- Resolver ID
- CaltechAUTHORS:20170825-154246193
- Philipps-Universität Marburg
- Max Planck Society
- Howard Hughes Medical Institute (HHMI)
- International Max Planck Research School for Environmental, Cellular and Molecular Microbiology
- Created
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2017-08-28Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field