3-DIMENSIONAL STRUCTURE OF EXTENDED CHROMATIN FIBERS AS REVEALED BY TAPPING-MODE SCANNING FORCE MICROSCOPY
3-DIMENSIONAL STRUCTURE OF EXTENDED CHROMATIN FIBERS AS REVEALED BY TAPPING-MODE SCANNING FORCE MICROSCOPY
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DOI：
10.1073/pnas.91.24.11621
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发表时间：
1994-11-22
影响因子：
11.1
通讯作者：
BUSTAMANTE, C
中科院分区：
文献类型：
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作者：
LEUBA, SH;YANG, GL;BUSTAMANTE, C
使用扫描力显微镜在环境湿度的空气中以轻敲模式操作，对极低盐含量的未固定鸡红细胞染色质纤维进行成像。这些图像揭示了纤维的三维组织。平面“之字形”构象很少见，而延伸的“串珠”纤维仅在组蛋白 H1 和 H5 耗尽的染色质中可见。戊二醛固定揭示了非常相似的结构。固定在 10 mM 盐中的纤维显得更加紧凑。与模型研究相比，这些结果表明，即使在低离子强度下，染色质纤维也可能以不规则的核小体三维阵列形式存在。
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.