Our results provide an explanation for how DNA replication is linked to sister chromatid cohesion establishment. A flapped or nicked DNA substrate constitutes a transient molecular clue that directs cohesin acetylation to a window behind the replication fork, next to where cohesin likely entraps both sister chromatids. Replication fork arrest is one of the quality control processes ensuring that DNA-dependent DNA replication occurs correctly. Both flaps and nicks stimulate cohesin acetylation, while subsequent nick ligation to complete Okazaki fragment maturation terminates the acetylation reaction. The enzymes that synthesize DNA according to the WatsonCrick. As polymerases complete lagging strand replication, strand displacement synthesis produces DNA flaps that are trimmed to result in nicked double-stranded DNA. Part of this replisome constitutes the enzymatic machinery around the replication fork. Biochemical reconstitution of replication-coupled cohesin acetylation reveals that transient DNA structures, which form during DNA replication, control the acetylation reaction. Here, we explore how cohesin acetylation is linked to DNA replication. Cohesion establishment requires acetylation of conserved cohesin lysine residues by Eco1 acetyltransferase. the DNA templates are antiparallel and yet the DNA polymerases only work in one direction. DNA polymerases can only synthesize DNA 3 to 5. Leading-strand synthesis proceeds continuously in the 5 to 3 direction. the helicase unwinds one strand faster than the other. There are two molecules of DNA polymerase III at a replication fork, each of them hard at work on one of the two new DNA strands. Concomitant with DNA replication, the chromosomal cohesin complex establishes cohesion between newly replicated sister chromatids. Each replication fork requires both leading and lagging strand synthesis because All of these are reasons.
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