Biology subjects

Vedyaykin, A. D.

Publications and source records attributed to Vedyaykin, A. D..

3 recordsLinked to original sources

bioRxiv2025

Interactions of the Escherichia coli SMC-like RecN protein with different forms of DNA revealed at the single-molecule level using optical tweezers

DNA molecule is the storage of genetic information in all living organisms. Its integrity is critical to life. However, due to the exposure to various environmental factors and endogenous agents, double-strand DNA breaks occur. Bacteria are capable to restore their genome integrity through a process called the SOS response. The key protein of SOS response is the RecA recombinase. Also critical for DNA repair is the SMC-like RecN protein, which helps RecA to find the homologous DNA template. Currently, its functions and mechanism of action remain poorly understood. In this work, using optical tweezers, we show predominant binding of RecN to ssDNA and also demonstrate a weak binding of dsDNA causing a condition similar to DNA loops formation.

biophysics↗

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↗

bioRxiv2024

Features of the DNA Escherichia coli RecN interaction revealed by fluorescence microscopy and single-molecule methods

The SOS response is a condition that occurs in bacterial cells after DNA damage. In this state, the bacterium is able to recover the integrity of its genome. Due to the increased level of mutagenesis in cells during the repair of DNA double-strand breaks, the SOS response is also an important mechanism for bacterial adaptation to the antibiotics. One of the key proteins of the SOS response is the SMC-like protein RecN, which helps the RecA recombinase to find a homologous DNA template for repair. In this work, the localization of the recombinant RecN protein in living Escherichia coli cells was revealed using fluorescence microscopy. It has been shown that the RecN, outside the SOS response, is predominantly localized at the poles of the cell, and in dividing cells, also localized at the center. Using in vitro methods including fluorescence microscopy and optical tweezers, we show that RecN predominantly binds single-stranded DNA in an ATP-dependent manner. RecN has both intrinsic and single-stranded DNA-stimulated ATPase activity. The results of this work may be useful for better understanding of the SOS response mechanism and homologous recombination process.

molecular biology↗