
<oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:title>Letter from Francis Crick to Aaron Klug</dc:title>
  <dc:subject>DNA</dc:subject>
  <dc:subject>Nucleosomes</dc:subject>
  <dc:description>Crick here commented further on the draft of a paper by Klug on the spatial arrangement of DNA and histones (proteins associated with DNA) in nucleosomes. Particularly, Crick debated the dimensions of the DNA helix in nucleosomes and how the DNA helix was itself coiled in a nucleosome (forming a coiled coil, or superhelix).  Nucleosomes have since been determined to consist of eight histone molecules wrapped by a DNA segment of about 150 base pairs in length. Under the electron microscope nucleosomes, which are linked to each other by DNA sequences about fifty base pairs in length, appear as bead-like bodies on a string.</dc:description>
  <dc:publisher>Produced: 20 June 1977</dc:publisher>
  <dc:contributor>The Wellcome Library for the History and Understanding of Medicine. Francis Harry Compton Crick Papers</dc:contributor>
  <dc:contributor></dc:contributor>
  <dc:contributor>Crick, Francis</dc:contributor>
  <dc:type>Letters (correspondence)</dc:type>
  <dc:format>Archival Materials</dc:format>
  <dc:format>Text</dc:format>
  <dc:format>2 pages</dc:format>
  <dc:identifier>nlm:nlmuid-101584582X232-doc</dc:identifier>
  <dc:identifier>101584582X232</dc:identifier>
  <dc:identifier>http://resource.nlm.nih.gov/101584582X232</dc:identifier>
  <dc:identifier>Profiles ID: SCBBQH</dc:identifier>
  <dc:language>English</dc:language>
  <dc:relation>Profiles in Science</dc:relation>
</oai_dc:dc>