Scientists identify key roadblock to gene expression

... transcription and we now are seeing the impact of nucleosome organization on RNA polymerase," said lead investi...mplex organisms like the fruit fly. In yeast, a nucleosome sits on top of the transcription start site, so RNA polymerase must contend with that nucleosome as soon as it begins to transcribe the gene. In c...

DNA Repair Proteins Monitored at Double-strand Break

...ucleosomesthe compact packages formed when strands of DNA wind around proteins, called histones, like thread around a spool. Disruption of the nucleosome at the site of a double-strand break allows the DNA to unravel and expose the area to repair proteins; the loss of functioning ATM and NBS1 blocks thi...

Scientists Map Key Landmarks in Human Genome

...This study presents the first global view of human nucleosome positioning," said Fisher. Although analyses of th...icated computational data analysis to pin down the nucleosome locations. The paper describes how the scientists ...er than in the DNA regions that are tied up by the nucleosome complexes. These results suggest that...

Nucleosome in Biological News

UC San Diego engineer provides insights to decades-old DNA squabble

...or heteromorphic chromatin fibers from analysis of nucleosome interactions." The authors include Gaurav Arya, a ...st that chromatin has a zigzag structure where the nucleosome chain follows a zigzag path along the chromatin fi...e fiber such that the linker DNA is straight. (The nucleosome is the basic unit of chromatin that consists of tw...

Researchers 'unzip' molecules to measure interactions keeping DNA packed in cells

...o understand what happens during that unwrapping process is at the heart of this research team's efforts. By unzipping each DNA double helix through a nucleosome using an optical trap -- a technique developed in Wang's lab -- they unwrapped strands of DNA from their histone cores, observing, with near-base pair...

Scripps Research scientists shed light on how DNA is unwound so that its code can be read

...scientists first found that it holds an individual nucleosome in what looks like a vise grip. They then found th...bulge in the DNA that can be propagated around the nucleosome and make possible translocation of the DNA with re... The researchers believe that by translocating a nucleosome along the DNA, RSC eventually slides into the next...

Media highlights in the January issues of Biophysical Journal

...exes. The ability of the DNA sequence itself to contribute significantly to nucleosome stability and DNA accessibility provides a mechanism for differential recog...es, such as those on key promoter elements. Significant sequence-dependence nucleosome stability is not widely-recognized but is potentially of fundamental import...

DNA repair proteins monitored at double-strand break

...srupt nucleosomes—the compact packages formed when strands of DNA wind around proteins, called histones, like thread around a spool. Disruption of the nucleosome at the site of a double-strand break allows the DNA to unravel and expose the area to repair proteins; the loss of functioning ATM and NBS1 blocks thi...

Latent memory of cells comes to life

...a specific DNA region. Changes can also happen during the lifetime of a cell due to chemical reactions allowing interconversions between the different nucleosome types. The effect of these changes can be that a latent capacity that was dormant comes to life, or, conversely, that a previously active capacity shu...

Scientists map key landmarks in human genome

...This study presents the first global view of human nucleosome positioning," said Fisher. Although analyses of th...icated computational data analysis to pin down the nucleosome locations. The paper describes how the scientists ...er than in the DNA regions that are tied up by the nucleosome complexes. These results suggest that...

Scientists reveal structure of gateways to gene control

... intimate relationship between the architecture of nucleosome structures and the underlying DNA sequences they r...A sequences are part of the control-center's H2A.Z nucleosome for each gene in the yeast genome. Also for the f...ters tend to be located on the outside edge of the nucleosome and tend to face outward on the DNA helix, allowin...

Penn researcher shows that DNA gets kinky easily at the nanoscale

... shouldn't spontaneously bend into such tight structures, yet it does," Nelson said. "In the conventional view of a DNA molecule, wrapping DNA into a nucleosome would be like bending a yardstick around a baseball." To study DNA on the needed short length scales, Nelson and his colleagues used a technique ...

Scientists discover a genetic code for organizing DNA within the nucleus

...the nucleus. What determines how, when and where a nucleosome will be positioned along the DNA sequence? Dr. Era... to day function, since access to DNA wrapped in a nucleosome is blocked for many proteins, including those resp... of the DNA is packaged into nucleosomes. A single nucleosome contains about 150 genetic bases (the "letters" th...

Nucleosome in Biological Products

Nucleosome ELISA Kit from Calbiochem

Description:...sorbance of unknown with that obtained from the standards, one can assign a nucleosome unit value to the unknown sample. Can be used to assign apoptotic index. O...l microtiter plate (12 removable strips) coated with a DNA binding protein, nucleosome standard, lysis buffer/sample diluent, biotinylated anti-histone 3 antibody...
Company:Calbiochem

Nucleosome in Biological Definition

Nucleosome

A nucleosome is the fundamental repeating subunit of eukayotic DNA , and is made up of DNA and histone proteins. It is found in the cell nucleus in eukaryotes . All chromatin (except for that packaged in the sperm nucleus) consists of nucleosomes. Nucleosomes can be seen with an ele...

Chromatin

...ed mainly by methylation and acylation of the nucleosome proteins. Chromatin structure is also of importa...e are three levels of chromatin organization: nucleosome - "beads on a string" 30 nm condensed chromatin...ffected mainly by methylation and acylation of the nucleosome proteins. Chromatin structure is also of importanc...

Histone

...own: H1 (sometimes called H5 .) H2A H2B H3 H4 Archaeal histones Two each of class H2A, H2B, H3 and H4 assemble to form one nucleosome , together with DNA. H1 is needed for histone-DNA-complexes to form a 30-nm fiber , which packs the DNA even more tightly. Functions Histones ...

Organelle

...some ribosome vacuole vesicle melanosome Other related structures: flagellum cytosol endomembrane system nucleosome microtubule cell membrane ...

Nucleosome in Biological Dictionary

Nucleosome

Nucleosomes form the fundamental repeating units of eukaryotic chromatin, which is used to pack the large eukaryotic genomes into the nucleus while still ensuring appropriate access to it . Nucleosomes are folded through a... nucleosome n. Any of the repeating subunits of chromatin, consisti...

Histone

...osomes to stabilize ... Histone proteins are among the most highly conserved proteins in eukaryotes, ... The linker histone H1 binds the nucleosome and the entry and exit sites of the ... The European Bioinformatics Institute ... IPR003958 Transcription factor CBF/NF-Y/archaeal histone ... ...

Chromatin

...se string-like fiber called chromatin , which condenses even ... Chromatin & Watson/Crick base pairing. Junction between B- and Z-DNA. The nucleosome ... In 1882 Walther Flemming used the term Chromatin for the first time. ... Nuclear function, Chromatin and Histones - The basic subunit of c...

Branch migration

...... RuvAB was found to promote branch migration , to dissociate the RecA filament, ... of RuvAB and ATP, rapid branch migration through the nucleosome is observed. ... Two models for the mechanism of branch migration were suggested. ... Holliday junction dynamics and branch migration : Sin...