title: Many ways to loop DNA.
abstract: In the 1960s, I developed methods for directly visualizing DNA and DNA-protein complexes using an electron microscope. This made it possible to examine the shape of DNA and to visualize proteins as they fold and loop DNA. Early applications included the first visualization of true nucleosomes and linkers and the demonstration that repeating tracts of adenines can cause a curvature in DNA. The binding of DNA repair proteins, including p53 and BRCA2, has been visualized at three- and four-way junctions in DNA. The trombone model of DNA replication was directly verified, and the looping of DNA at telomeres was discovered.
authors.affiliation: From the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7295.
authors.forename: Jack D
authors.initials: JD
authors.lastname: Griffith
mesh_terms: D024682:BRCA2 Protein / Q000378:metabolism / Q000648:ultrastructure; D004247:DNA / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000648:ultrastructure*; D008854:Microscopy, Electron / Q000379:methods*; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D024682:BRCA2 Protein; D004268:DNA-Binding Proteins; D009707:Nucleosomes; D016159:Tumor Suppressor Protein p53; D004247:DNA
keywords: Chromatin; DNA; Electron Microscopy (EM); Nucleotide; Telomeres