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Structural basis of HMCES interactions with abasic DNA and multivalent substrate recognition

HMCES can covalently crosslink to abasic sites in single-stranded DNA at stalled replication forks to prevent genome instability. Here, we report crystal structures of the Human HMCES SRAP domain in complex with DNA-damage substrates, including HMCES crosslinked with an abasic site within a 3’ overh...

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Detalles Bibliográficos
Autores principales: Halabelian, Levon, Ravichandran, Mani, Li, Yanjun, Zeng, Hong, Rao, Anjana, Aravind, L., Arrowsmith, Cheryl H
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609482/
https://www.ncbi.nlm.nih.gov/pubmed/31235913
http://dx.doi.org/10.1038/s41594-019-0246-6
Descripción
Sumario:HMCES can covalently crosslink to abasic sites in single-stranded DNA at stalled replication forks to prevent genome instability. Here, we report crystal structures of the Human HMCES SRAP domain in complex with DNA-damage substrates, including HMCES crosslinked with an abasic site within a 3’ overhang DNA. HMCES interacts with both single-strand and duplex segments of DNA, with two independent duplex DNA interaction sites identified in the SRAP domain. The HMCES DNA-protein crosslink structure provides structural insights into a novel thiazolidine covalent interaction between the DNA abasic site and conserved Cys2 of HMCES. Collectively, our structures demonstrate the capacity for the SRAP domain to interact with variety of single-strand and double-strand containing DNA structures found in DNA-damage sites including 5’ and 3’ overhang DNAs and gapped DNAs with short single-strand segments.