期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：1
页码：69-73
DOI：10.1073/pnas.74.1.69
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Nucleoli isolated from HeLa cells are functionally active but contain large amounts of RNA and proteins (RNA/DNA ratio 1:1; protein/DNA ratio 7:1). We have isolated from the nucleolus a DNA-protein complex that has the characteristics of nucleolar chromatin (RNA/DNA ratio less than 0.05:1; protein/DNA ratio 1.7:1). This nucleolar chromatin has most of the transcriptional activity of the intact nucleolus and, as assayed by circular dichroism and dye binding, has largely preserved its structure. The isolation of a transcriptionally active, fragment of chromatin, which constitutes only a small part of the total genome and codes for only one recognizable product, offers several advantages for the study of chromatin structure and function.
