A key event in bacterial cell division is the formation of the septum, whose main component is FtsZ , a conserved protein, widely distributed and that polymerizes forming the Z ring at the center of the cell. In addition to FtsZ, a group of different proteins participates in the cell division and the Z ring formation. This ring is capable of contracting and being a protein scaffold for other dividing proteins. Super-resolution microscopy has revealed that the structure of the Z ring is discontinuous in models such as Escherichia coli and Bacillus subtilis.
Cyanobacteria are morphologically diverse, there are: unicellular, filamentous (with division in a plane) and branched (with division in more than one plane). The divisome of cyanobacteria possesses elements common to gram positive and negative bacteria, in addition to exclusive proteins. Our group is interested in the identification of new proteins that participate in the cell division of filamentous cyanobacteria (our model is Anabaena sp. PCC7120). Through the generation of mutants that inactivate specific genes and fusion mutants with GFP, we have characterized the function of the cydiv gene, a new protein identified in cyanobacteria, and also we have characterized in depth the expression and subcellular localization of FtsZ.
CyDiv is key in the location of the cellular septum and the integrity of the cell membrane. FtsZ forms a discontinuous Z ring with characteristics that allow us to propose an assembly model in filamentous cyanobacteria.