Search results for "Linker DNA"
showing 3 items of 3 documents
Subrepeats result from regional DNA sequence conservation in tandem repeats in Chironomus telomeres
1990
Repeat units, widespread in eukaryotic genomes, are often partially or entirely built up of subrepeats. Homogenization between whole repeat units arranged in tandem usually can best be understood as a result of unequal crossing over. Such a mechanism is less plausible for maintaining similarities between subrepeats within a repeat unit when present in a regular array. In Chironomus telomeres, large blocks of tandemly repeated approximately 350 base-pair units contain two or three pairs of subrepeats with high mutual identities, embedded in linker DNA, non-repetitive within the repeat unit. Measurements of evolutionary base changes in two closely related species, Chironomus tentans and Chiro…
Use of the Transglutaminase Reaction To Study the Dissociation of Histone N-Terminal Tails from DNA in Nucleosome Core Particles
1997
We have recently shown that core histones are glutaminyl substrates for transglutaminase (TGase) and that when native nucleosome cores are incubated with monodansylcadaverine (DNC) as donor amine, this fluorescent probe is incorporated into Gln5 and Gln19 of H3 and in Gln22 of H2B [Ballestar et al. (1996) J. Biol. Chem. 271, 18817-18825]. In the present paper, we report that the cause by which Gln22 of H2B is modified in nucleosomes but not in the free histone is the interaction of the region containing that glutamine with DNA. We have used the specificity of the TGase reaction to study the changes induced by increasing ionic strength in the interaction between the histone N-terminal tails …
Acetylated nucleosome assembly on telomeric DNAs
2003
Abstract The role of histone N-terminal domains on the thermodynamic stability of nucleosomes assembled on several different telomeric DNAs as well as on ‘average’ sequence DNA and on strong nucleosome positioning sequences, has been studied by competitive reconstitution. We find that histone tails hyperacetylation favors nucleosome formation, in a similar extent for all the examined sequences. On the contrary, removal of histone terminal domains by selective trypsinization causes a decrease of nucleosome stability which is smaller for telomeres compared to the other sequences examined, suggesting that telomeric sequences have only minor interactions with histone tails. Micrococcal nuclease…