Essential dynamic interdependence of FtsZ and SepF for Z-ring and septum formation in Corynebacterium glutamicum

Adrià Sogues, Mariano Martinez, Quentin Gaday, Mathilde Ben-Assaya, Martin Graña, Alexis Voegele, Michael VanNieuwenhze, Patrick England, Ahmed Haouz, Alexandre Chenal, Sylvain Trépout, Rosario Duran, Anne Marie Wehenkel, Pedro Alzari

Sep 06, 2019

Received Date: 28th August 19

The mechanisms of Z-ring assembly and regulation in bacteria are poorly understood, particularly in non-model organisms. Actinobacteria, one of the largest bacterial phyla that includes the deadly human pathogen Mycobacterium tuberculosis, lack the canonical FtsZ-membrane anchors as well as all positive and negative Z-ring regulators described for E. coli. Here we investigate the physiological function of Corynebacterium glutamicum SepF, the only cell division-associated protein from Actinobacteria known to directly interact with the conserved C-terminal tail of FtsZ but whose actual mode of action in cytokinesis is yet to be elucidated. We used a mechanistic cell biology approach to unveil the essential interdependence of FtsZ and SepF required for the formation of a functional Z-ring in the actinobacterial model organism C. glutamicum. The crystal structure of the SepF-FtsZ complex reveals a hydrophobic FtsZ-binding pocket, which defines the SepF homodimer as the functional unit, and a reversible oligomerization interface regulated via an alpha helical switch. FtsZ filaments and lipid membranes have opposing effects on SepF polymerization, leading to a complex dynamic role of the protein at the division site, involving FtsZ bundling, Z-ring tethering and membrane reshaping activities that are needed for proper Z-ring assembly and function.

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This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.

Nature Communications

Nature Research, Springer Nature