The effect of Escherichia coli min proteins on Bacillus subtilis
Ján Jamrokovič, Naďa Pavlendová, Katarína Muchová and Imrich Barák
Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21,
845 51 Bratislava, Slovakia
In Gram-positive Bacillus subtilis and in Gram-negative E. coli, min proteins are involved in the regulation of division septa positioning. In both systems the concentration gradient of FtsZ inhibitor MinCD is formed from poles to cell centre. In E. coli MinE protein drives the oscillation of MinCD from pole to pole by binding to MinD and ATP hydrolysis. In this way, the lowest concentration of MinCD inhibitors at the cell centre is forming. In B. subtilis MinCD complex is targeted to the cell poles by MinJ and DivIVA protein. They retain MinCD at the cell poles. Such concentration gradient from poles to cell centre allows FtsZ-ring formation at the cell centre and at the same time prevents asymmetric division to take place at the cell poles. Heterologous expression of MinCEc and MinDEc has an effect on B. subtilis cell length. Moreover MinDEc partially substitutes for the function of its B. subtilis counterpart and localizes similarly on helices along the cell axis as B. subtilis MinD.
Here using yeast two hybrid system we show direct interactions between MinD E. coli and MinC B. subtilis. Additionally, we observed dynamic behavior of MinDEc and MinE in B. subtilis when expressed together. All these findings indicate that these two Min systems resemble each other more than it was thought previously.
This work was supported by the grant APVT-51-027804, No. ESF-EC-0106, LPP-0218-06 and VEGA grant 2/0016/10 from the Slovak Academy of Sciences and The Wellcome Trust Grant 082829/Z/07/Z