scholarly journals The prenucleosome, a stable conformational isomer of the nucleosome

2015 ◽  
Vol 29 (24) ◽  
pp. 2563-2575 ◽  
Author(s):  
Jia Fei ◽  
Sharon E. Torigoe ◽  
Christopher R. Brown ◽  
Mai T. Khuong ◽  
George A. Kassavetis ◽  
...  
Keyword(s):  
Motor Protein ◽  
Upstream Region ◽  
Entry And Exit ◽  
Core Particle ◽  
Nucleosome Core Particle ◽  
Nucleosome Core ◽  
Histone Octamer ◽  
Conformational Isomer

Chromatin comprises nucleosomes as well as nonnucleosomal histone–DNA particles. Prenucleosomes are rapidly formed histone–DNA particles that can be converted into canonical nucleosomes by a motor protein such as ACF. Here we show that the prenucleosome is a stable conformational isomer of the nucleosome. It consists of a histone octamer associated with ∼80 base pair (bp) of DNA, which is located at a position that corresponds to the central 80 bp of a nucleosome core particle. Monomeric prenucleosomes with free flanking DNA do not spontaneously fold into nucleosomes but can be converted into canonical nucleosomes by an ATP-driven motor protein such as ACF or Chd1. In addition, histone H3K56, which is located at the DNA entry and exit points of a canonical nucleosome, is specifically acetylated by p300 in prenucleosomes relative to nucleosomes. Prenucleosomes assembled in vitro exhibit properties that are strikingly similar to those of nonnucleosomal histone–DNA particles in the upstream region of active promoters in vivo. These findings suggest that the prenucleosome, the only known stable conformational isomer of the nucleosome, is related to nonnucleosomal histone–DNA species in the cell.

scholarly journals X-ray structure of the MMTV-A nucleosome core

2016 ◽  
Vol 113 (5) ◽  
pp. 1214-1219 ◽  
Author(s):  
Timothy D. Frouws ◽  
Sylwia C. Duda ◽  
Timothy J. Richmond
Keyword(s):  
Dna Sequence ◽  
Dna Sequences ◽  
Promoter Sequence ◽  
Core Particle ◽  
Nucleosome Core Particle ◽  
Particle Structure ◽  
X Ray ◽  
Nucleosome Core ◽  
Sequence Dependent

The conformation of DNA bound in nucleosomes depends on the DNA sequence. Questions such as how nucleosomes are positioned and how they potentially bind sequence-dependent nuclear factors require near-atomic resolution structures of the nucleosome core containing different DNA sequences; despite this, only the DNA for two similar α-satellite sequences and a sequence (601) selected in vitro have been visualized bound in the nucleosome core. Here we report the 2.6-Å resolution X-ray structure of a nucleosome core particle containing the DNA sequence of nucleosome A of the 3′-LTR of the mouse mammary tumor virus (147 bp MMTV-A). To our knowledge, this is the first nucleosome core particle structure containing a promoter sequence and crystallized from Mg2+ ions. It reveals sequence-dependent DNA conformations not seen previously, including kinking into the DNA major groove.

How does the histone code work?

2005 ◽  
Vol 83 (4) ◽  
pp. 468-476 ◽  
Author(s):  
Michael S Cosgrove ◽  
Cynthia Wolberger
Keyword(s):  
Chromatin Structure ◽  
Histone Code ◽  
Globular Domain ◽  
Core Particle ◽  
Nucleosome Core Particle ◽  
Histone Tails ◽  
Post Translational Modifications ◽  
Nucleosome Core ◽  
Histone Octamer ◽  
Nucleosome Dynamics

Patterns of histone post-translational modifications correlate with distinct chromosomal states that regulate access to DNA, leading to the histone-code hypothesis. However, it is not clear how modification of flexible histone tails leads to changes in nucleosome dynamics and, thus, chromatin structure. The recent discovery that, like the flexible histone tails, the structured globular domain of the nucleosome core particle is also extensively modified adds a new and exciting dimension to the histone-code hypothesis, and calls for the re-examination of current models for the epigenetic regulation of chromatin structure. Here, we review these findings and other recent studies that suggest the structured globular domain of the nucleosome core particle plays a key role regulating chromatin dynamics.Key words: histones, histone code, modifications, epigenetic, chromatin, nucleosome, dynamics, regulated nucleosome mobility, core, archaeal, combinatorial switch, histone octamer.

scholarly journals The role of the PZP domain of AF10 in acute leukemia driven by AF10 translocations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Anagha Deshpande ◽  
Khan L. Cox ◽  
Fan Xuan ◽  
Mohamad Zandian ◽  
...  
Keyword(s):  
Critical Role ◽  
Cellular Transformation ◽  
Acute Leukemias ◽  
Hematopoietic Stem ◽  
Nucleosome Core ◽  
Stem And Progenitor Cells ◽  
Transforming Activity

AbstractChromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.

scholarly journals Structure of the yeast nucleosome core particle reveals fundamental changes in internucleosome interactions

2001 ◽  
Vol 20 (18) ◽  
pp. 5207-5218 ◽  
Author(s):  
Cindy L. White ◽  
Robert K. Suto ◽  
Karolin Luger
Keyword(s):  
Core Particle ◽  
Nucleosome Core Particle ◽  
Nucleosome Core
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