Three-dimensional structure of extended chromatin fibers as revealed by tapping-mode scanning force microscopy

TitleThree-dimensional structure of extended chromatin fibers as revealed by tapping-mode scanning force microscopy
Publication TypeJournal Article
Year of Publication1994
AuthorsLeuba S.H, Yang G., Robert C., Samori B., van Holde K., Zlatanova J., Bustamante C.
JournalProc. Natl. Acad. Sci. U.s.a.
Volume91
Pagination11621–11625
Date Publishednov
KeywordsAnimals, Atomic Force, Biological, Chickens, Chromatin, Fixatives, Histones, Microscopy, Models, Non-P.H.S., Non-U.S. Gov't, Osmolar Concentration, P.H.S., Research Support, Sodium Chloride, U.S. Gov't
Abstract

Unfixed chicken erythrocyte chromatin fibers in very low salt have been imaged with a scanning force microscope operating in the tapping mode in air at ambient humidity. These images reveal a three-dimensional organization of the fibers. The planar "zig-zag" conformation is rare, and extended "beads-on-a-string" fibers are seen only in chromatin depleted of histones H1 and H5. Glutaraldehyde fixation reveals very similar structures. Fibers fixed in 10 mM salt appear somewhat more compacted. 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.

Citation Key1994|1968