Letter from Aaron Klug to Francis Crick


Title:
Letter from Aaron Klug to Francis Crick
Description:
Klug here discussed his and Crick's ideas about chromosome structure in light of his X-ray diffraction studies of chromatin, the name given to the chromosomal material when extracted from the nucleus of cells in higher organisms. Only short stretches of pure helical DNA appear on the chromosomes, while most chromosomal DNA is surrounded by a mesh of proteins and is highly folded and coiled.. Crick used the image of a solenoid, a long, regular, hollow cylindrical structure, in thinking about the way in which DNA and its associated proteins are organized into the tightly folded and coiled conformation in which they are found on the chromosomes. He postulated that chromatids, the one-half of a chromosome that splits off from the other half during cell division, were organized in a hierarchy of helices: the chromatid is a folded and coiled super-solenoid, also called the unit fiber, which in turn is formed by a coiled solenoid of smaller diameter, which in turn is formed by coiling the string of nucleosomes, bead-like complexes of DNA and protein.
Extent:
2 pages
Date Created:
21 October 1976
Creator:
Klug, Aaron (Aaron Klug)
Recipient:
Crick, Francis, 1916-2004
Source:
Original Repository. Wellcome Library for the History and Understanding of Medicine. Francis Harry Compton Crick Papers. 11646. URL. http://archives.wellcome.ac.uk/
Original Repository:
The Wellcome Library for the History and Understanding of Medicine. Francis Harry Compton Crick Papers
Right Type:
Permission Granted - No Conditions
Right Statement:
Reproduced with permission of Aaron Klug.
Subject:
Crystallography, X-Ray and Chromatin
Profiles in Science ID:
SCBBPW
NLM ID:
101584582X223
Genre:
Letters (correspondence)
Language:
English
Format:
Text
Location:
Box: 23. Folder: PP/CRI/D/2/18