A conserved cell division protein directly regulates FtsZ dynamics in filamentous and unicellular actinobacteria

• Published in: eLife Vol. 10
• Main Authors: Ramos-León, Félix, Bush, Matthew J, Sallmen, Joseph W, Chandra, Govind, Richardson, Jake, Findlay, Kim C, McCormick, Joseph R, Schlimpert, Susan
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 17.03.2021; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Binding sites; Cell division; Cell Division - genetics; Comparative analysis; Contractility; Cytokinesis; Cytoskeletal Proteins - genetics; Cytoskeletal Proteins - metabolism; Filaments; FtsZ; Localization; Microbiology and Infectious Disease; Microscopy; Mycobacterium smegmatis; Mycobacterium smegmatis - genetics; prokaryotic development; Proteins; Septum; sporulation; Streptomyces - genetics; Streptomyces venezuelae; FtsZ; Streptomyces venezuelae; infectious disease; prokaryotic development; Mycobacterium smegmatis; cell division; microbiology; sporulation
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.63387

Bacterial cell division is driven by the polymerization of the GTPase FtsZ into a contractile structure, the so-called Z-ring. This essential process involves proteins that modulate FtsZ dynamics and hence the overall Z-ring architecture. Actinobacteria like and lack known key FtsZ-regulators. Here we report the identification of SepH, a conserved actinobacterial protein that directly regulates FtsZ dynamics. We show that SepH is crucially involved in cell division in and that it binds FtsZ via a conserved helix-turn-helix motif, stimulating the assembly of FtsZ protofilaments. Comparative studies using the SepH homolog from further reveal that SepH can also bundle FtsZ protofilaments, indicating an additional Z-ring stabilizing function . We propose that SepH plays a crucial role at the onset of cytokinesis in actinobacteria by promoting the assembly of FtsZ filaments into division-competent Z-rings that can go on to mediate septum synthesis.