Holliday Junctions Formed from Human Telomeric DNA.
Shozeb M HaiderPengfei LiSoraia KhialiDeeksha MunnurArvind RamanathanGary N ParkinsonPublished in: Journal of the American Chemical Society (2018)
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.
Keyphrases
- induced apoptosis
- single molecule
- endothelial cells
- cell cycle arrest
- circulating tumor
- cell free
- induced pluripotent stem cells
- dna repair
- endoplasmic reticulum stress
- papillary thyroid
- randomized controlled trial
- signaling pathway
- pluripotent stem cells
- clinical trial
- deep learning
- dna damage response
- young adults
- copy number
- pi k akt
- cell proliferation
- dna methylation
- squamous cell
- childhood cancer
- circulating tumor cells