Alcohol is broken down in the body into acetaldehyde, a toxic chemical that can damage DNA by creating interstrand crosslinks (AA-ICL). These crosslinks block DNA replication and threaten the stability of the genome. A rare genetic disease, Fanconi anaemia (FA), is marked by extreme sensitivity to DNA crosslinking agents, including acetaldehyde. Although the Fanconi anaemia DNA repair pathway is known to fix this type of damage, exactly how it repairs acetaldehyde crosslinks is not yet understood. Here we show that the FA nuclease Slx4-Xpf-Ercc1 (SXE) plays a key role in the repair of AA-ICL. Using a DNA replication fork with site-specific AA-ICL, we show that SXE specifically excises this crosslink, highlighting its role in the repair of alcohol-induced DNA interstrand crosslinks. Moreover, SXE performs two precise incisions flanking the AA-ICL and can similarly repair a basic-site DNA interstrand crosslink. These results expand our understanding of how the FA pathway resolves alcohol-induced DNA damage. In addition, they suggest that SXE is a versatile nuclease complex and may be involved in repairing other types of crosslinks that may activate the FA pathway.

• MeSH
• acetaldehyd MeSH
• DNA vazebné proteiny * metabolismus   genetika   MeSH
• endonukleasy * metabolismus   genetika   MeSH
• ethanol * toxicita   MeSH
• Fanconiho anemie * genetika   metabolismus   MeSH
• lidé MeSH
• oprava DNA * účinky léků   MeSH
• poškození DNA MeSH
• reagencia zkříženě vázaná MeSH
• rekombinasy * metabolismus   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetaldehyd MeSH
• DNA vazebné proteiny * MeSH
• endonukleasy * MeSH
• ERCC1 protein, human MeSH Prohlížeč
• ethanol * MeSH
• reagencia zkříženě vázaná MeSH
• rekombinasy * MeSH
• SLX4 protein, human MeSH Prohlížeč
• xeroderma pigmentosum group F protein MeSH Prohlížeč

Covalent DNA interstrand crosslinks are toxic DNA damage lesions that block the replication machinery that can cause a genomic instability. Ubiquitous abasic DNA sites are particularly susceptible to spontaneous cross-linking with a base from the opposite DNA strand. Detection of a crosslink induces the DNA helicase ubiquitination that recruits NEIL3, a DNA glycosylase responsible for the lesion removal. NEIL3 utilizes several zinc finger domains indispensable for its catalytic NEI domain repairing activity. They recruit NEIL3 to the repair site and bind the single-stranded DNA. However, the molecular mechanism underlying their roles in the repair process is unknown. Here, we report the structure of the tandem zinc-finger GRF domain of NEIL3 and reveal the molecular details of its interaction with DNA. Our biochemical data indicate the preferential binding of the GRF domain to the replication fork. In addition, we obtained a structure for the catalytic NEI domain in complex with the DNA reaction intermediate that allowed us to construct and validate a model for the interplay between the NEI and GRF domains in the recognition of an interstrand cross-link. Our results suggest a mechanism for recognition of the DNA replication X-structure by NEIL3, a key step in the interstrand cross-link repair.

• MeSH
• DNA-glykosylasy metabolismus   MeSH
• DNA-helikasy metabolismus   MeSH
• DNA chemie   MeSH
• endodeoxyribonukleasy metabolismus   MeSH
• jednovláknová DNA MeSH
• oprava DNA * MeSH
• poškození DNA MeSH
• zinek MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA-glykosylasy MeSH
• DNA-helikasy MeSH
• DNA MeSH
• endodeoxyribonukleasy MeSH
• jednovláknová DNA MeSH
• NEIL3 protein, mouse MeSH Prohlížeč
• zinek MeSH

Oxidatively-generated interstrand cross-links rank among the most deleterious DNA lesions. They originate from abasic sites, whose aldehyde group can form a covalent adduct after condensation with the exocyclic amino group of purines, sometimes with remarkably high yields. We use explicit solvent molecular dynamics simulations to unravel the structures and mechanical properties of two DNA sequences containing an interstrand cross-link. Our simulations palliate the absence of experimental structural and stiffness information for such DNA lesions and provide an unprecedented insight into the DNA embedding of lesions that represent a major challenge for DNA replication, transcription and gene regulation by preventing strand separation. Our results based on quantum chemical calculations also suggest that the embedding of the ICL within the duplex can tune the reaction profile, and hence can be responsible for the high difference in yields of formation.

• MeSH
• algoritmy MeSH
• DNA chemie   MeSH
• konformace nukleové kyseliny * MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• simulace molekulární dynamiky * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA MeSH