Biomaterial Database

Isolation of transcriptionally active chromatin from mammalian nucleoli. 1977

B M Bombik, and C H Huang, and R Baserga

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.

UI	MeSH Term	Description	Entries
D002466	Cell Nucleolus	Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)	Plasmosome,Cell Nucleoli,Nucleoli, Cell,Nucleolus, Cell,Plasmosomes
D002843	Chromatin	The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.	Chromatins
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D012260	Ribonucleases	Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.	Nucleases, RNA,RNase,Acid Ribonuclease,Alkaline Ribonuclease,Ribonuclease,RNA Nucleases,Ribonuclease, Acid,Ribonuclease, Alkaline
D013698	Templates, Genetic	Macromolecular molds for the synthesis of complementary macromolecules, as in DNA REPLICATION; GENETIC TRANSCRIPTION of DNA to RNA, and GENETIC TRANSLATION of RNA into POLYPEPTIDES.	Genetic Template,Genetic Templates,Template, Genetic
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription