Mycoplasma gallisepticum FtsZ demonstrates properties that distinguish it from other known homologs

In bacteria, cell division usually occurs through binary fission, with the participation of genes from the dcw cluster. In mollicutes, this cluster is significantly reduced -- often only the ftsZ, ftsA, mraZ, and mraW genes remain, and sometimes ftsZ is completely absent. FtsZ is a key division protein that forms the Z-ring, but its role in mollicutes is questionable due to the absence of many cell division proteins and the cell wall. In the current study, we investigated the FtsZ protein of Mycoplasma gallisepticum, a bacterium with a reduced set of putative cell division genes (ftsZ, ftsA, ftsK). The results show that, unlike in well-studied bacteria, FtsZ in M. gallisepticum often exhibits polar rather than mid-cell localization. Overexpression of fluorescently labeled FtsZ enhances this polar localization and may lead to minicell formation. The FtsZ concentration was measured and, together with in vitro data, confirmed its ability to polymerize, similar to its homologs. Protein-protein interactions were also analyzed and confirmed the link of FtsZ to cell division. Overall, the results support the role of FtsZ in cell division, though its properties differ significantly from other known homologs.