Association of nucleosome core particle DNA with different histone oligomers

Aragay, Anna M.; Dı́az, Pilar; Daban, Joan‐Ramon

doi:10.1016/0022-2836(88)90605-5

Cited by 30 publications

(54 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The curves are displaced vertically by an arbitrary amount for clarity. mobility of core particles and DNA-(H3,H4) complexes on nondenaturing gels (Aragay et al, 1988(Aragay et al, ,1991 does not change after X-ray irradiation (not shown). Nucleosome core particles in the different buffers used in the study of the DNA-histone complexes considered below show a radius of gyration of 4.2 nm ( Table I).…”

Section: Synchrotron X-ray Solution Scattering Measurementsmentioning

confidence: 78%

“…In fact, it has been found previously using circular dichroism and fluorescence spectroscopy (00-hara & Wada, 1987), and nucleoprotein gel electrophoresis, sedimentation, chemical cross-linking, trypsin and nuclease digestions, and thermal denaturation (Aragay et al, 1988), that histones H2A,H2B in the absence of H3,H4 can form various thermodynamically stable complexes with DNA at This work was supported in part by a DGICYT grant (PB86-0029). Synchrotron radiation experiments performed at SERC Daresbury Laboratory (Warrington, U.K.) were supported by the European Community Large Scale Facilities Programme.…”

mentioning

confidence: 84%

“…The different DNA-histone samples werecentrifuged for 2 min at lOOOOg, and the resulting supernatant was used for the X-ray scattering measurements. After irradiation, samples were analyzed on nondenaturing 6% polyacrylamide gels containing 0.1 XTBE as described previously (Aragay et al, 1988). X-ray Scattering.…”

Section: Methodsmentioning

confidence: 99%

“…Core histones, nucleosome core particles, and core DNA [ 146 base pairs (bp)] I were prepared from chicken erythrocyte nuclei as described (Diaz & Daban, 1986;Aragay et al, 1988). The histone pairs H2A,H2B and H3,H4 were prepared from core histones by chromatography on a Sephadex G-100 (superfine) column, eluted with 0.2 M NaCI, 0.4 mM phenylmethanesulfonyl fluoride, 0.03% 2-mercaptoethanol, and 10 mM Tris-HC1, pH 7.4 (Aragay et al, 1991).…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Unfolded structure and reactivity of nucleosome core DNA-histone H2A,H2B complexes in solution as studied by synchrotron radiation X-ray scattering

Samsó¹,

Daban²

1993

Biochemistry

View full text Add to dashboard Cite

It has been previously found using different physicochemical techniques [Aragay, A., Diaz, P., & Daban, J.-R. (1988) J. Mol. Biol. 204, 141-154] that histones H2A,H2B in the absence of H3,H4 can associate with nucleosome core DNA (146 base pairs). Here we describe a synchrotron X-ray scattering study of core DNA-(H2A,H2B) complexes in solution. Our results obtained using different histone to DNA weight ratios and ionic conditions ranging from very low ionic strength to 0.2 M NaCl show that histones H2A,H2B are unable to fold core DNA. Model calculations indicate that histones H2A,H2B produce very elongated structures even when the reconstituted complexes are prepared at physiological ionic strength. In contrast, our scattering data indicate that the reconstituted complexes prepared at physiological salt concentration either with the four core histones or with histones H3,H4 without H2A,H2B are completely folded particles with a radius of gyration similar to that corresponding to the native nucleosome core (4.2 nm). Furthermore, our results show that the DNA of the extended complexes containing histones H2A,H2B becomes completely folded after the histone pair exchange reaction that occurs spontaneously between preformed DNA-(H2A,H2B) and DNA-(H3,H4) complexes. These observations, together with our previous studies, suggest that the open conformation of DNA-(H2A,H2B) complexes facilitates the involvement of this structure as a transient intermediate in the reaction of nucleosome formation at physiological ionic strength.

show abstract

Section: Synchrotron X-ray Solution Scattering Measurementsmentioning

confidence: 78%

mentioning

confidence: 84%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Unfolded structure and reactivity of nucleosome core DNA-histone H2A,H2B complexes in solution as studied by synchrotron radiation X-ray scattering

Samsó¹,

Daban²

1993

Biochemistry

View full text Add to dashboard Cite

show abstract

“…1a). The relative retardation of the mononucleosome band produced by this nondenaturing agarose gel is lower than that observed in low ionic strength polyacrylamide gels (37). Nevertheless, whereas oligonucleosomes cannot enter the polyacrylamide gels (38), the agarose gels described in this work can be used even with chromatin samples of high molecular weight.…”

Section: Behavior Of Chromatin Fragments Of Different Molecular Weighmentioning

confidence: 93%

Electrophoresis of Chromatin on Nondenaturing Agarose Gels Containing Mg2+

Bartolomé

Bermúdez

Daban

1995

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

We show that nondenaturing agarose gels can be used for the study of the structure and dynamic properties of native (uncross-linked) chromatin. In gels containing 1.7 mM Mg 2؉ , chicken erythrocyte chromatin fragments having from about 6 to 50 nucleosomes produce well defined bands. These bands have an electrophoretic mobility that decreases only slightly with molecular weight. This surprising behavior is not observed in low ionic strength gels. Fragments with less than 6 nucleosomes and low content of histones H1-H5 give rise to broad bands in gels with Mg 2؉. In contrast, fragments containing only 3-4 nucleosomes but with the normal H1-H5 content are able to form associated structures with a mobility similar to that observed for high molecular weight chromatin. Electron microscopy results indicate that the associated fragments and the fragments of higher molecular weight show similar electrophoretic properties because they become very compact in the presence of Mg 2؉ and form cylindrical structures with a diameter of ϳ33 nm. Our results suggest that the interactions involved in the self-assembly of small fragments are the same that direct the folding of larger fragments; in both cases, the resulting compact chromatin structure is formed from a basic element containing 5-7 nucleosomes.In chromatin an octamer of histones H2A, H2B, H3, and H4 associated with 146 bp 1 of DNA forms the core of the nucleosome (1, 2). The two turns of DNA (about 165 bp) around these core histones are sealed by histone H1 (H5 in avian erythrocytes) (3-5). Nucleosomes connected by linker DNA form a filament that can fold into a condensed chromatin fiber of about 30 nm in diameter (reviewed in Ref. 6).The mechanism of chromatin folding and the structure of the 30-nm fiber have been studied by sedimentation methods (7-9), enzymatic and chemical digestions (10 -12), electric, flow, and photochemical dichroism (13-15), x-ray diffraction (16, 17), small angle x-ray scattering (18 -20), neutron scattering (21, 22), transmission electron microscopy (23-32), and scanning force microscopy (33). The results obtained in these studies have suggested different models for the folding and structural organization of the 30-nm chromatin fiber. These models differ essentially in the location of the linker DNA. In the one-start helix models, the linker DNA is folded and connects laterally consecutive nucleosomes (8,13,17,23,32). In the twistedribbon models, a two-start helix is formed by pairs of nucleosomes with the linker DNA parallel to the fiber axis (24, 26). Finally, in several continuous (11,18,28) and discontinuous (27) crossed-linker models, and in the variable zigzag nucleosomal ribbon model (30, 31), the linker DNA is extended in the fiber interior.In this work we show that nondenaturing agarose gel electrophoresis can be used for the study of the folding of chromatin. We have found that, when electrophoresis is performed in the presence of Mg 2ϩ , chicken erythrocyte chromatin fragments of a relatively high molecular weight change dramaticall...

show abstract

Nucleosome assembly in vitro: separate histone transfer and synergistic interaction of native histone complexes purified from nuclei of Xenopus laevis oocytes.

1990

View full text Add to dashboard Cite

High speed supernatants of Xenopus laevis oocyte nuclei efficiently assemble DNA into nucleosomes in vitro under physiological salt conditions. The assembly activity cofractionates with two histone complexes composed of the acidic protein N1/N2 in complex with histones H3 and H4, and nucleoplasmin in complex with histones H2B and H2A. Both histone complexes have been purified and their nucleosome assembly activities have been analysed separately and in combination. While the histones from the N1/N2 complexes are efficiently transferred to DNA and induce supercoils into relaxed circular plasmid DNA, the nucleoplasmin complexes show no supercoil induction, but can also transfer their histones to DNA. In combination, the complexes act synergistically in supercoil induction thereby increasing the velocity and the number of supercoils induced. Electron microscopic analysis of the reaction products shows fully packaged nucleoprotein structures with the typical nucleosomal appearance resulting in a compaction ratio of 2.8 under low ionic strength conditions. The high mobility group protein HMG‐1, which is also present in the soluble nuclear homogenate from X. laevis oocytes, is not required for nucleosome core assembly. Fractionation experiments show that the synergistic effect in the supercoiling reaction can be exerted by histones H3 and H4 bound to DNA and the nucleoplasmin complexes alone. This indicates that it is not the synchronous action of both complexes which is required for nucleosome assembly, but that their cooperative action can be resolved into two steps: deposition of H3 and H4 from the N1/N2 complexes onto the DNA and completion of nucleosome core formation by addition of H2B and H2A from the nucleoplasmin complexes.

show abstract

Association of nucleosome core particle DNA with different histone oligomers

Cited by 30 publications

References 60 publications

Unfolded structure and reactivity of nucleosome core DNA-histone H2A,H2B complexes in solution as studied by synchrotron radiation X-ray scattering

Unfolded structure and reactivity of nucleosome core DNA-histone H2A,H2B complexes in solution as studied by synchrotron radiation X-ray scattering

Electrophoresis of Chromatin on Nondenaturing Agarose Gels Containing Mg2+

Nucleosome assembly in vitro: separate histone transfer and synergistic interaction of native histone complexes purified from nuclei of Xenopus laevis oocytes.

Contact Info

Product

Resources

About