PT - JOURNAL ARTICLE AU - Aleksandr Alekseev AU - Georgii Pobegalov AU - Natalia Morozova AU - Alexey Vedyaykin AU - Galina Cherevatenko AU - Alexander Yakimov AU - Dmitry Baitin AU - Mikhail Khodorkovskii TI - A new insight into RecA filament regulation by RecX from the analysis of conformation-specific interactions AID - 10.1101/2022.03.14.484239 DP - 2022 Jan 01 TA - bioRxiv PG - 2022.03.14.484239 4099 - http://biorxiv.org/content/early/2022/03/14/2022.03.14.484239.short 4100 - http://biorxiv.org/content/early/2022/03/14/2022.03.14.484239.full AB - RecA protein mediates homologous recombination repair in bacteria through assembly of long helical filaments on single-stranded DNA (ssDNA) in an ATP dependent manner. RecX, an important negative regulator of RecA, is known to inhibit RecA activity by stimulating the disassembly of RecA nucleoprotein filaments. Here we use a single-molecule approach to address the regulation of (E. coli) RecA-ssDNA filaments by RecX (E. coli) within the framework of distinct conformational states of RecA-ssDNA filament. Our findings revealed that RecX effectively binds the inactive conformation of RecA-ssDNA filaments and slows down the transition to the active state. Results of this work provide new mechanistic insights into the RecX-RecA interactions and highlight the importance of conformational transitions of RecA filaments as an additional level of regulation of its biological activity.Competing Interest StatementThe authors have declared no competing interest.