The convergence of head-on DNA unwinding forks induces helicase oligomerization and activity transition.

ABSTRACT: Helicases are multifunctional motor proteins with the primary task of separating nucleic acid duplexes. These enzymes often exist in distinct oligomeric forms and play essential roles during nucleic acid metabolism. Whether there is a correlation between their oligomeric state and cellular function, and how helicases effectively perform functional switching remains enigmatic. Here, we address these questions using a combined single-molecule approach and Bloom syndrome helicase (BLM). By examining the head-on collision of two BLM-mediated DNA unwinding forks, we find that two groups of BLM, upon fork convergence, promptly oligomerize across the fork junctions and tightly bridge two independent single-stranded (ss) DNA molecules that were newly generated by the unwinding BLMs. This protein o

SUBMITTER: Bi L 

PROVIDER: S-EPMC9191346 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature