Acetylated nucleosome assembly on telomeric DNAs.
The role of histone N-terminal domains on the thermodynamic stability of nucleosomes assembled on several different telomeric DNAs as well as on 'average' sequence DNA and on strong nucleosome positioning sequences, has been studied by competitive reconstitution. We find that histone tails hyperacetylation favors nucleosome formation, in a similar extent for all the examined sequences. On the contrary, removal of histone terminal domains by selective trypsinization causes a decrease of nucleosome stability which is smaller for telomeres compared to the other sequences examined, suggesting that telomeric sequences have only minor interactions with histone tails. Micrococcal nuclease kinetics shows enhanced accessibility of acetylated nucleosomes formed both on telomeric and 'average' sequence DNAs. These results suggest a more complex role for histone acetylation than the decrease of electrostatic interactions between DNA and histones.
Cacchione
Stefano
S
Dipartimento di Genetica e Biologia Molecolare, Fondazione Istituto Pasteur-Fondazione Cenci Bolognetti, Università di Roma La Sapienza, Piazzale A. Moro 5, 00185, Roma, Italy.
Luis Rodríguez
José
J
Mechelli
Rosella
R
Franco
Luis
L
Savino
Maria
M
D000107:Acetylation; D000818:Animals; D001667:Binding, Competitive; D002696:Chlamydomonas; D004247:DNA / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007716:Kluyveromyces; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016615:Telomere / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013816:Thermodynamics
D006657:Histones; D009707:Nucleosomes; D004247:DNA; D008836:Micrococcal Nuclease