Membrane affinity difference between MinD monomer and dimer is not crucial for MinD gradient formation in <i>Bacillus subtilis</i>
Proteins can diffuse micrometers in seconds, yet bacterial cells are able to maintain stable protein gradients. The best-studied bacterial protein gradient is the Min system of Escherichia coli . In rod-shaped bacteria, the MinCD proteins prevent formation of minicells by inhibiting FtsZ polymerization close to the cell poles. In E. coli , these proteins oscillate between cell poles within a…
Proteins can quickly diffuse across bacterial cells, yet maintaining stable protein gradients remains a challenge. The Min system in Escherichia coli is the most studied example. MinCD proteins stop minicell formation by inhibiting FtsZ polymerization near the cell poles. In E. coli, MinD and MinE switch between monomeric and dimeric membrane-attached forms, creating an oscillating gradient at cell poles via an ATP-driven reaction-diffusion system.
Bacillus subtilis possesses MinCD but lacks MinE, forming a static gradient with the transmembrane protein MinJ at cell poles and sites of division.
A recent model recreated the B. subtilis MinD gradient by assuming MinD cycles between the cytosol and membrane, similar to E. coli. This study reveals that the monomeric and dimeric states of B. subtilis MinD have similar membrane affinities. MinD also interacts with MinJ as a dimer, but MinJ is not required for the membrane localization of MinD.
Using kinetic Monte Carlo simulations, researchers tested various models and found that a difference in diffusion rates between the monomer and dimer, rather than a difference in membrane affinity, is crucial for the formation of the B. subtilis MinCD gradient.
Written by urgent.news from eLife's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
