Biomaterial Database

Studies on synthetic chromatins containing poly(dA-dT) X poly(dA-dT) and poly(dG-dC) X poly(dG-dC). 1983

P E Prevelige, and G D Fasman

Core histones (H2A,H2B,H3,H4)2, were reconstituted with the synthetic polynucleotides poly(dA-dT) X poly(dA-dT) and poly(dG-dC) X poly(dG-dC) to yield synthetic chromatins containing 200 basepairs per octamer. These synthetic chromatins displayed a 36% decrease in the circular dichroism (CD) peak ellipticity from the value of the polynucleotide free in solution; the poly(dA-dT) X poly(dA-dT)/chromatin showed an increase in the complexity of the thermal denaturation profile compared to that of the polynucleotide. Both the temperature of maximum dh/dT for each transition (Tm) and the relative amount of poly(dA-dT) X poly(dA-dT) in the synthetic chromatin melting in each of the four thermal transitions is a function of the ionic strength over the 0-5 mM sodium phosphate range (0.25 mM EDTA, pH 7.0); a shift of material toward higher melting transitions was observed with increasing ionic strength. The CD peak ellipticity value for both synthetic chromatins was ionic strength-independent over the 0-5 mM sodium phosphate range. These results are in contrast to those observed with H1/H5 stripped chicken erythrocyte chromatin (Fulmer, A. and Fasman, G.D. (1979) Biopolymers 18, 2875-2891), where an ionic strength dependence was found. Differences in the CD spectra between poly(dA-dT) X poly(dA-dT)/chromatin, poly(dG-dC) X poly(dG-dC)/chromatin and H1/H5 stripped chicken erythrocyte chromatin suggest subtle differences in assembly. Finally, the temperature dependence of the CD spectra of poly(dA-dT) X poly(dA-dT)-containing synthetic chromatin, which is similar to that for the polynucleotide, suggests the core histone bound polynucleotide has a large degree of conformational flexibility allowing it to undergo the premelt transition.

UI	MeSH Term	Description	Entries
D008957	Models, Genetic	Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Genetic Models,Genetic Model,Model, Genetic
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D011067	Poly dA-dT	Polydeoxyribonucleotides made up of deoxyadenine nucleotides and thymine nucleotides. Present in DNA preparations isolated from crab species. Synthetic preparations have been used extensively in the study of DNA.	Poly(Deoxyadenylate-Thymidylate),Polydeoxyadenine Nucleotides-Polythymine Nucleotides,Poly dA dT,Poly(dA-dT),d(A(5)T(5))2,Nucleotides, Polydeoxyadenine Nucleotides-Polythymine,Nucleotides-Polythymine Nucleotides, Polydeoxyadenine,Polydeoxyadenine Nucleotides Polythymine Nucleotides,dA dT, Poly,dA-dT, Poly,dT, Poly dA
D011089	Polydeoxyribonucleotides	A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.	Polydeoxyribonucleotide
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D002843	Chromatin	The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.	Chromatins
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D006657	Histones	Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.	Histone,Histone H1,Histone H1(s),Histone H2a,Histone H2b,Histone H3,Histone H3.3,Histone H4,Histone H5,Histone H7
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia