Control of septum thickness by the curvature of SepF polymers
Journal article, 2021
Gram-positive bacteria divide by forming a thick cross wall. How the thickness of this septal wall is controlled is unknown. In this type of bacteria, the key cell division protein FtsZ is anchored to the cell membrane by two proteins, FtsA and/or SepF. We have isolated SepF homologs from different bacterial species and found that they all polymerize into large protein rings with diameters varying from 19 to 44 nm. Interestingly, these values correlated well with the thickness of their septa. To test whether ring diameter determines septal thickness, we tried to construct different SepF chimeras with the purpose to manipulate the diameter of the SepF protein ring. This was indeed possible and confirmed that the conserved core domain of SepF regulates ring diameter. Importantly, when SepF chimeras with different diameters were expressed in the bacterial host Bacillus subtilis, the thickness of its septa changed accordingly. These results strongly support a model in which septal thickness is controlled by curved molecular clamps formed by SepF polymers attached to the leading edge of nascent septa. This also implies that the intrinsic shape of a protein polymer can function as a mold to shape the cell wall.
FtsZ
SepF
cell division
Bacillus subtilis
Author
Michaela Wenzel
University of Amsterdam
Chalmers, Biology and Biological Engineering, Chemical Biology
Ilkay N. Celik Gulsoy
University of Amsterdam
Yongqiang Gao
Harvard Medical School
University of Amsterdam
Zihao Teng
University of Amsterdam
Joost Willemse
Leiden University
Martijn Middelkamp
University of Groningen
Mariska G. M. van Rosmalen
Vrije Universiteit Amsterdam
Per W. B. Larsen
University of Amsterdam
Nicole N. van der Wel
University of Amsterdam
Gijs J. L. Wuite
Vrije Universiteit Amsterdam
Wouter H. Roos
University of Groningen
Leendert W. Hamoen
University of Amsterdam
Proceedings of the National Academy of Sciences of the United States of America
0027-8424 (ISSN) 1091-6490 (eISSN)
Vol. 118 2 e2002635118Subject Categories
Biochemistry and Molecular Biology
Microbiology
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
DOI
10.1073/pnas.2002635118
PubMed
33443155