6GDH

Holliday Junctions formed from Telomeric DNA

Summary for 6GDH

• Entry DOI: 10.2210/pdb6gdh/pdb
• Descriptor: DNA (5'-D(*CP*TP*AP*AP*CP*CP*CP*TP*AP*A)-3'), DNA (5'-D(*TP*TP*AP*GP*GP*GP*TP*TP*AP*G)-3') (2 entities in total)
• Functional Keywords: holliday junction, homologous recombination, telomeres, alt mechanism, acc structural motif., recombination
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 8
• Total formula weight: 24352.13

Authors

Parkinson, G.N.,Haider, S.,Li, P.,Khiali, S.,Munnur, D.,Ramanathan, A. (deposition date: 2018-04-23, release date: 2018-11-07, Last modification date: 2024-01-17)

Primary citation

Haider, S.,Li, P.,Khiali, S.,Munnur, D.,Ramanathan, A.,Parkinson, G.N.
Holliday Junctions Formed from Human Telomeric DNA.
J. Am. Chem. Soc., 140:15366-15374, 2018

PubMed Abstract: Cells have evolved inherent mechanisms, like homologous recombination (HR), to repair damaged DNA. However, repairs at telomeres can lead to genomic instability, often associated with cancer. While most rapidly dividing cells employ telomerase, the others maintain telomere length through HR-dependent alternative lengthening of telomeres (ALT) pathways. Here we describe the crystal structures of Holliday junction intermediates of the HR-dependent ALT mechanism. Using an extended human telomeric repeat, we also report the crystal structure of two Holliday junctions in close proximity, which associate together through strand exchange to form a hemicatenated double Holliday junction. Our combined structural results demonstrate that ACC nucleotides in the C-rich lagging strand (5'-CTAACCCTAA-3') at the telomere repeat sequence constitute a conserved structural feature that constrains crossover geometry and is a preferred site for Holliday junction formation in telomeres.

PubMed: 30376323
DOI: 10.1021/jacs.8b08699

Experimental method

X-RAY DIFFRACTION (2.85 Å)