Homologous recombination repairs DNA double-strand breaks (DSB) using an intact dsDNA molecule as a template. It entails a homology search step, carried out along a conserved RecA/Rad51-ssDNA filament assembled on each DSB end. Whether, how and to what extent a DSB impacts chromatin folding, and how this (re)organization in turns influences the homology search process, remain ill-defined. Here we characterize two layers of spatial chromatin reorganization following DSB formation in Saccharomyces cerevisiae. Although cohesin folds chromosomes into cohesive arrays of ~20-kb-long chromatin loops as cells arrest in G2/M, the DSB-flanking regions interact locally in a resection- and 9-1-1 clamp-dependent manner, independently of cohesin, Mec1, Rad52 and Rad51. This local structure blocks cohesin progression, constraining the DSB region at the base of a loop. Functionally, cohesin promotes DSB-dsDNA interactions and donor identification in cis, while inhibiting them in trans. This study identifies multiple direct and indirect ways by which cohesin regulates homology search during recombinational DNA repair.
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http://dx.doi.org/10.1038/s41556-021-00783-x | DOI Listing |
Nucleic Acids Res
January 2025
School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Tailor-made enzymes empower a wide range of versatile applications, although searching for the desirable enzymes often requires high throughput screening and thus poses significant challenges. In this study, we employed homology searches and protein language models to discover and prioritize enzymes by their kinetic parameters. We aimed to discover kynureninases as a potentially versatile therapeutic enzyme, which hydrolyses L-kynurenine, a potent immunosuppressive metabolite, to overcome the immunosuppressive tumor microenvironment in anticancer therapy.
View Article and Find Full Text PDFPathogens
December 2024
School of Artificial Intelligence, Hangzhou Dianzi University, Hangzhou 310018, China.
is a parasite transmitted by mosquitoes and can cause a neglected tropical disease called Lymphatic filariasis. However, the genome of was not well studied, making novel drug development difficult. This study aims to identify microRNA, annotate protein function, and explore the pathogenic mechanism of by genome-wide analysis.
View Article and Find Full Text PDFGenes (Basel)
December 2024
Project Group Biochemistry, Leibniz Institute on Aging-Fritz Lipmann Institute, D-07745 Jena, Germany.
DNA replication represents a series of precisely regulated events performed by a complex protein machinery that guarantees accurate duplication of the genetic information. Since DNA replication is permanently faced by a variety of exogenous and endogenous stressors, DNA damage response, repair and replication must be closely coordinated to maintain genomic integrity. HROB has been identified recently as a binding partner and activator of the Mcm8/9 helicase involved in DNA interstrand crosslink (ICL) repair.
View Article and Find Full Text PDFCAZymes ( C arbohydrate A ctive En Zymes ) degrade, synthesize, and modify all complex carbohydrates on Earth. CAZymes are extremely important to research in human health, nutrition, gut microbiome, bioenergy, plant disease, and global carbon recycling. Current CAZyme annotation tools are all based on sequence similarity.
View Article and Find Full Text PDFCell Rep
January 2025
Laboratory of Biochemistry, Wageningen University, 6708 WE Wageningen, the Netherlands. Electronic address:
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