The 3.6 Å Structure of the Reovirus Core Particle

Although the crystal structure of nucleosome core particle is essentially symmetrical in the vicinity of the dyad, the linker histone binds asymmetrically in this region to select a single high-affinity site from potentially two equivalent sites. To try to resolve this apparent paradox we mapped to base-pair resolution the dyads and rotational settings of nucleosome core particles reassembled on synthetic tandemly repeating 20 bp DNA sequences. In agreement with previous observations, we observed (1) that the helical repeat on each side of the dyad cluster is 10 bp maintaining register with the sequence repeat and (2) that this register changes by 2 bp in the vicinity of the dyad. The additional 2 bp required to effect the change in the rotational settings is accommodated by an adjustment immediately adjacent to the dyad. At the dyad the hydroxyl radical cleavage is asymmetric and we suggest that the inferred structural asymmetry could direct the binding of the linker histone to a single preferred site.

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Halobacterium cutirubrum ribosomes. Properties of the ribosomal proteins and ribonucleic acid

Biochemical Journal ◽

10.1042/bj1300103 ◽

1972 ◽

Vol 130 (1) ◽

pp. 103-110 ◽

Cited By ~ 51

Author(s):

L. P. Visentin ◽

C. Chow ◽

A. T. Matheson ◽

M. Yaguchi ◽

F. Rollin

Keyword(s):

Ribosomal Protein ◽

Ribosomal Proteins ◽

Soluble Fraction ◽

Ribosomal Subunit ◽

23S Rrna ◽

Core Particle ◽

Fractionation Procedure ◽

Additional Protein ◽

70S Ribosome ◽

Low Ionic Strength

1. The 30S ribosomal subunit of the extreme halophile Halobacterium cutirubrum is unstable and loses 75% of its ribosomal protein when the 70S ribosome is dissociated into the two subunits. A stable 30S subunit is obtained if the dissociation of the 70S particle is carried out in the presence of the soluble fraction. 2. A fractionation procedure was developed for the selective removal of groups of proteins from the 30S and 50S subunits. When the ribosomes, which are stable in 4m-K+ and 0.1m-Mg2+, were extracted with low-ionic-strength buffer 75–80% of the 30S proteins and 60–65% of the 50S proteins as well as the 5S rRNA were released. The proteins in this fraction are the most acidic of the H. cutirubrum ribosomal proteins. Further extraction with Li+–EDTA releases additional protein, leaving a core particle containing either 16S rRNA or 23S rRNA and about 5% of the total ribosomal protein. The amino acid composition, mobility on polyacrylamide gels at pH4.5 and 8.7, and the molecular-weight distribution of the various protein fractions were determined. 3. The s values of the rRNA are 5S, 16S and 23S. The C+G contents of the 16S and 23S rRNA were 56.1 and 58.8% respectively and these are higher than C+G contents of the corresponding Escherichia coli rRNA (53.8 and 54.1%).

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3.9 Å structure of the nucleosome core particle determined by phase-plate cryo-EM

Nucleic Acids Research ◽

10.1093/nar/gkw708 ◽

2016 ◽

Vol 44 (17) ◽

pp. 8013-8019 ◽

Cited By ~ 56

Author(s):

Eugene Y.D. Chua ◽

Vinod K. Vogirala ◽

Oviya Inian ◽

Andrew S.W. Wong ◽

Lars Nordenskiöld ◽

...

Keyword(s):

Phase Plate ◽

Core Particle ◽

Nucleosome Core Particle ◽

Nucleosome Core

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