How Min systems from Clostridia
species helps to find the mid-cell site during cell division?
E. Krascsenitsová, J. Makroczyová, N. Labajová, J.
Jamroškovič and I. Barák
Department of Microbial Genetics, Institute
of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21,
845 51 Bratislava, Slovakia, E-mail: firstname.lastname@example.org
division begins with polymerization of FtsZ protein
and formation of Z‑ring, which marks the future site
of the septum at the
mid-cell. Z-ring serves as a scaffold for division
proteins, and its proper placement is crucial for subsequent steps in cell
division. In rod-shaped bacteria, one of the mechanisms
responsible for correct placement of the division
septum is the Min system. The action of Min system creates a concentration gradient
of division inhibitor MinC, which is highest at the cell poles and lowest at
the midcell. The underlying
mechanism fundamentally differs
between Escherichia coli and Bacillus subtilis though, the core
components of the Min system, MinC and MinD, are evolutionary conserved. MinC, the direct inhibitor of FtsZ polymerization, is attracted to the membrane via MinD,
whose localisation is in turn dependent on another
protein/s called topological
determinant. While in E. coli MinD protein
undergoes rapid pole-to-pole oscillation driven by MinE protein, in B. subtilis MinD is anchored to the cell poles via
In our previous study, we have shown that oscillating Min
system of E. coli can be transplanted into B. subtilis. Interestingly,
strains in which oscillation was observed were impaired in sporulation at the
step of asymmetric septum formation . The finding that oscillating Min system is not compatible
with sporulation might partially explain why two Min
systems with such distinct mechanism evolved for two different life cycles,
vegetative growth and sporulation. Genome-wide search for Min system homologues
in selected Gram-positive endospore-forming bacteria revealed that they harbour various
combinations of homologues from both Min systems.
Two of the species carrying a combination of Min proteins
from both systems Clostridium difficile (MinCDE, DivIVA) and Clostridium
beijerinckii (MinCDE, MinJ/DivIVA) have been chosen for our further
studies. Here we show the oscillatory behaviour of
MinDE proteins of the two
clostridial species in B. subtilis cells and investigate protein-protein interactions between Min proteins of these
organisms . We evaluated the effects of expression of these
proteins on sporulation of B. subtilis.
1. J. Jamroškovič, N.
Pavlendová, K. Muchová, A.J. Wilkinson, I. Barák, Microbiology, 2012, 158, 1972.
2. J. Makroczyová, J.
Jamroškovič, E. Krascsenitsová, N. Pavlendová and I. Barák. Microbiol. Open, 2016, doi: 10.1002/mbo3.337
This work was
supported by Grant 2/0009/13 from the Slovak Academy of Sciences and by a Grant
from the Slovak Research and Development Agency under contract APVV-14-018.