Evolved sequence features within the intrinsically disordered tail influence FtsZ assembly and bacterial cell division

Megan C. Cohan; Ammon E. Posey; Steven J. Grigsby; Anuradha Mittal; Alex S. Holehouse; Paul J. Buske; Petra A. Levin; Rohit V. Pappu

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/301622 doi: bioRxiv preprint different amounts of KCl. For WT and CTLV4, bundling decreases as salt concentration increases. (G) Comparative assessments of GTPase activity -normalized to the WT FtsZ -for CTLV4 and ∆CTT. Polymerization weakens the GTPase activity and this auto-inhibition derives from the presence of the tail. This point is made by comparing the efficiencies of GTP hydrolysis for CTLV4 and ∆CTT to that of the WT FtsZ. The efficiencies are shown normalized to that of WT. Absence of the CTT leads to an enzyme that almost three times more efficient as a GTPase when compared to the WT or CTLV4. The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. (Lempel and Ziv, 1976 ) of each of the nine CTT sequences including those from WT FtsZ and the eight designed variants. Calculations of the LZ sequence complexities were performed using localCider The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/301622 doi: bioRxiv preprint mediated process. Polymerization and bundling increases the effective valence of the CTP, shown in pink. In the absence of GTP, FtsZ subunits exist primarily as monomers and small oligomers. As CTT κ is increased above 0.4, the interactions amongst CTTs alter the FtsZ assembly mechanism. In the presence of GTP, high κ FtsZ variants form large linear polymers that become laterally zippered through stable CTT-CTT interactions, forming a train track-like morphology thereby inhibiting GTP hydrolysis and slowing down subunit turnover. In the absence of GTP, FtsZ interactions amongst CTTs lead to the formation of spherical assemblies that are stabilized in higher salt concentrations.