3-DIMENSIONAL STRUCTURE OF EXTENDED CHROMATIN FIBERS AS REVEALED BY TAPPING-MODE SCANNING FORCE MICROSCOPY

Authors
LEUBA SH YANG GL ROBERT C SAMORI B VANHOLDE K ZLATANOVA J BUSTAMANTE C
Citation
Sh. Leuba et al., 3-DIMENSIONAL STRUCTURE OF EXTENDED CHROMATIN FIBERS AS REVEALED BY TAPPING-MODE SCANNING FORCE MICROSCOPY, Proceedings of the National Academy of Sciences of the United Statesof America, 91(24), 1994, pp. 11621-11625
Citations number
38
Categorie Soggetti
Multidisciplinary Sciences
Journal title
Proceedings of the National Academy of Sciences of the United Statesof America → ACNP
ISSN journal
00278424
Volume
91
Issue
24
Year of publication
1994
Pages
11621 - 11625
Database
ISI
SICI code
0027-8424(1994)91:24<11621:3SOECF>2.0.ZU;2-M
Abstract
Unfixed chicken erythrocyte chromatin fibers in very low salt have bee n imaged with a scanning force microscope operating in the tapping mod e in air at ambient humidity. These images reveal a three dimensional organization of the fibers. The planar ''zig-zag'' conformation is rar e, and extended ''beads-on-a-string'' fibers are seen only in chromati n depleted of histones H1 and H5. Glutaraldehyde fixation reveals very similar structures. Fibers fixed in 10 mM salt appear somewhat more c ompacted, These results, when compared with modeling studies, suggest that chromatin fibers may exist as irregular three-dimensional arrays of nucleosomes even at low ionic strength.