Biology subjects

Rumyantseva, N. A.

Publications and source records attributed to Rumyantseva, N. A..

3 recordsLinked to original sources

bioRxiv2025

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.

molecular biology↗

bioRxiv2025

Ureaplasma parvum SMC-ScpAB complex is capable of loop extrusion and demonstrates properties that distinguish it from Bacillus subtilis homologue

Structural Maintenance of Chromosomes (SMC) complexes are present in virtually all organisms and perform a variety of functions associated with maintaining the integrity and spatial organization of DNA. The best-studied SMC complexes are eukaryotic condensins, cohesins, and Smc5/Smc6. It is extremely important that eukaryotic SMC have been shown to exhibit the ability for so-called loop extrusion in vitro, which is the active formation of loops from DNA molecules and is a cosequence of the DNA translocase activity of SMC complexes. For majority of bacterial SMC complexes, including the most widespread Smc-ScpAB complex, loop extrusion has not yet been demonstrated in vitro, although it is in good agreement with the results of in vivo experiments. In this work, we compared the properties of two Smc-ScpAB complexes from different organisms, Bacillus subtilis and Ureaplasma parvum. The results of the work indicate significant differences in the properties of these homologous complexes. In particular, the Smc-ScpAB complex of U. parvum was shown to have the ability to extrude loops, which was not observed for B. subtilis SMC.

molecular biology↗

bioRxiv2024

Properties of the Ureaplasma parvum SMC protein related to its interaction with DNA

SMC (Structural Maintenance of Chromosomes) ATPase proteins are integral components of complexes bearing the same name, crucial for the spatial organization of DNA across diverse life forms, spanning bacteria, archaea, and eukaryotes. It is proposed that in bacteria, SMC complexes facilitate DNA compaction through loop extrusion and aid in the segregation of daughter nucleoids. In this paper the properties of the SMC ATPase protein from Ureaplasma parvum were investigated by using a spectrum of methods, including conventional biochemical methods as well as advanced single-molecule techniques. Our findings reveal distinctive properties of this protein compared to its extensively studied homologue from Bacillus subtilis. Notably, our results suggest that U. parvum SMC ATPase facilitates DNA compaction even in the absence of ATP.

molecular biology↗