Please use this identifier to cite or link to this item: http://lib.jncasr.ac.in:8080/jspui/handle/10572/432
Title: DNA- and Chromatin-Condensing Properties of Rat Testes Hla and Hlt Compared to Those of Rat Liver Hlbdec: Hlt Is a Poor Condenser of Chromatin
Authors: Khadake, Jyoti R
Rao, M R S
Keywords: C-Terminal Domain
Globular Domain
Histone H-1
Cooperative Binding
Circular-Dichroism
H5
Hybridization
Organization
Localization
Subtypes
Issue Date: 15-Dec-1995
Publisher: American Chemical Society
Citation: Biochemistry 34(48), 15792-15801 (1995)
Abstract: Histones H1a and H1t are two major linker histone variants present at the pachytene interval of mammalian spermatogenesis. The DNA- and chromatin-condensing properties of these two variants isolated from rat testes were studied and compared with those from rat liver. For this purpose, the histone H1 subtypes were purified from the respective tissues using bath acid and salt extraction procedures, Circular dichroism studies revealed that acid exposure during isolation affects the alpha-helical structure of both the globular domain (in the presence of 1 M NaCl) and the C-terminal lambda-tail (in the presence of 60% trifluoroethanol). The condensation of rat oligonucleosomal DNA, as measured by circular dichroism spectroscopy, by the salt-extracted histone H1 was at least 10 times more efficient than condensation by the acid-extracted histone H1. A site size of 16-20 base pairs was calculated for the salt-extracted histone H1. Among the different histone H1 subtypes, somatic histone H1bdec had the highest DNA-condensing property, followed by histone H1a and histone H1t. All the salt-extracted histones condensed rat oligonucleosomal DNA more efficiently than linear pBR-322 DNA, Histones H1bdec and H1a condensed histone H1-depleted chromatin, prepared from rat liver nuclei, with relatively equal efficiency. On the other hand, there was no condensation of histone H1-depleted chromatin with the testes specific histone H1t. A comparison of the amino acid sequences of histone H1d (rat) and histone H1t (rat) revealed several interesting differences in the occurrence of DNA-binding motifs at the C-terminus. A striking observation is the presence of a direct repeat of an octapeptide motif K(A)T(S)PKKA(S)K(T)K(A) in histone H1d that is absent in histone H1t.
Description: Restricted Access
URI: http://hdl.handle.net/10572/432
Other Identifiers: 0006-2960
Appears in Collections:Research Papers (M.R.S. Rao)

Files in This Item:
File Description SizeFormat 
sl.no.77.1995 Biochemistry , 34, 15792-15801.pdf
  Restricted Access
3.04 MBAdobe PDFView/Open Request a copy


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.