Characterization of subunits of transcriptionally active and inactive chromatin of Yoshida ascites tumour cells: composition and transcription functions
Ramakrishnan, N.; Patil, M.S.; Pradhan, D.S.
Indian Journal of Biochemistry and Biophysics 20(1): 1-7
1983
ISSN/ISBN: 0301-1208 PMID: 6642536 Document Number: 220822
Ascites chromatin was fractionated into transcriptionally active and inactive regions by selective shearing of chromatin from ascites nuclei with DNase-II followed by separating the released portion on the basis of its solubility properties in 2 mM MgCl2. The subunits of transcriptionally active and inactive chromations could be separated by Biogel A-5 m column. Using the same column it was possible to determine the sizes of DNA contained in the isolated chromatin subunits. Both transcriptionally active and inactive fractions of chromatin contain nucleosomes of 200 base pairs of DNA and histone components H2A, H2B, H3, H4 and H1. The subunits of transcriptionally active chromatin region possess both RNA chain initiation sites and template activity whereas those obtained from inactive chromatin region were virtually devoid of any transcription functions.