The distinct contributions of histone tails and their acetylation to nucleosomal stability were examined by mechanical disruption of individual nucleosomes in a single chromatin fiber using an optical trap. Enzymatic removal of H2A/H2B tails primarily decreased the strength of histone-DNA interactions located approximately +/-36bp from the dyad axis of symmetry (off-dyad strong interactions), w...

Analysis of cloned sequences for yeast histone genes H2A and H2B reveals that there are only two copies of this pair of genes within the haploid yeast genome. Within each copy, the genes for H2A and H2B are separated by approximately 700 bp of spacer DNA. The two copies are separated from one another in the yeast genome by a minimum distance of 35-60 kb. Sequence homology between the two copies...

Saccharomycotina and Taphrinomycotina lack intron in their histone genes, except for an intron in one of histone H4 genes of Yarrowia lipolytica. On the other hand, Basidiomycota and Perizomycotina have introns in their histone genes. We compared the distributions of 81, 47, 79, and 98 introns in the fungal histone H2A, H2B, H3, and H4 genes, respectively. Based on the multiple alignments of th...

We have studied the sample concentration-dependent and external stress-dependent stability of native and reconstituted nucleosomal arrays. Whereas upon stretching a single chromatin fiber in a solution of very low chromatin concentration the statistical distribution of DNA length released upon nucleosome unfolding shows only one population centered around approximately 25 nm, in nucleosome stab...

Not all members of the human histone gene family are functional. We have isolated a human H2B pseudogene that contains alterations in the protein-coding sequences as well as in the 3' and 5' flanking sequences that preclude expression of a functional H2B histone protein. There are three modifications in the amino acid-coding region: a single-base deletion producing a frame shift, a single-base ...

Promoter chromatin disassembly is a widely used mechanism to regulate eukaryotic transcriptional induction. Delaying histone H3/H4 removal from the yeast PHO5 promoter also leads to delayed removal of histones H2A/H2B, suggesting a constant equilibrium of assembly and disassembly of H2A/H2B, whereas H3/H4 disassembly is the highly regulated step. Toward understanding how H3/H4 disassembly is re...

Unique subunits Swp82, Taf14, Snf6, Snf11 Rsc3,5,7,9, 10,30, Htl1, Ldb7, and Rtt102 INO80 regulates transcription and is involved in DNA repair and cellcycle checkpoint adaptation. It has ATP-dependent nucleosome mobilization activity in vitro. SWR1 regulates transcription and is also involved in deposition of histone H2AZ, chromosome stability, and cell-cycle checkpoint adaptation. In vitro it...

Analogues of a synthetic heptapeptide substrate corresponding to the sequence around a phosphorylation site in histone H2B [Glass, D. B. & Krebs, E. G. (1982) J. Biol. Chem. 257, 1196-1200] were used to assess interactions between the peptide substrate and the ATP binding sites of cGMP-dependent protein kinase and the catalytic subunit of cAMP-dependent protein kinase. The affinity of each prot...

UNLABELLED Elongins B and C are members of complexes that increase the efficiency of transcriptional elongation by RNA polymerase II (RNAPII) and enhance the monoubiquitination of histone H2B, an epigenetic mark of actively transcribed genes. Here we show that, in addition to its role in facilitating transcription of the cellular genome, elongin B also enhances gene expression from the double-s...

Histones are essential components of chromatin structure, and histone modification plays an important role in various cellular functions including transcription, gene silencing, and immunity. Histones also play distinct roles in extrachromosomal settings. Extrachromosomal histone H2B acts as a cytosolic sensor to detect double-stranded DNA (dsDNA) fragments derived from infectious agents or dam...