Higher-order structure of human mitotic chromosomes.
Abstract
From observations on the partial disintegration of isolated human metaphase chromosomes we propose that human metaphase chromatids have a rather simple organization based on the folding and coiling of a long, regular, hollow cylindrical structure with a diameter of about 4000 A. This cylindrical structure, the unit fiber, is postulated to be a super-solenoid formed by the coiling of a 300 A solenoid, itself composed by coiling the basic string of nucleosomes. The structure of a human chromatid would thus be a hierarchy of helices, the contraction ratio of each coil, in ascending order of size, being approximately 7, 6, 40, and 5. This model appears to explain the estimated mass/unit length and accounts for many of the known features of human mitotic chromatids.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- April 1977
- DOI:
- 10.1073/pnas.74.4.1595
- Bibcode:
- 1977PNAS...74.1595B