UV-induced pyrimidine dimers and trimethylpsoralen cross-links do not alter chromatin folding in vitro.
Biochemistry
; 27(19): 7197-205, 1988 Sep 20.
Article
em En
| MEDLINE
| ID: mdl-3207669
ABSTRACT
We have examined the ability of intact and histone H1 depleted chromatin fibers to fold into higher ordered structures in vitro following DNA damage by two different agents UV irradiation at 254 nm and trimethylpsoralen plus near-UV light. Both agents damage DNA specifically, yet cause different degrees of unwinding (and possibly bending) of the DNA helix. In addition, trimethylpsoralen forms interstrand DNA cross-links. The structural transitions of intact and histone H1 depleted chromatin fibers, induced by NaCl, were monitored by analytical ultracentrifugation, light scattering, and circular dichroism. Our results indicate that when chromatin fibers contain even large, nonphysiological amounts of DNA photodamage by either agent, the salt-induced folding of these fibers into higher ordered structures is unaffected. The compact 30-nm fiber must therefore be able to accommodate a large amount of DNA photodamage (greater than one UV-induced photoproduct or trimethylpsoralen interstrand cross-link per nucleosome) with little or no change in the overall size or compaction of this structure.
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Base de dados:
MEDLINE
Assunto principal:
Furocumarinas
/
Dímeros de Pirimidina
/
Trioxsaleno
/
Raios Ultravioleta
/
Dano ao DNA
/
Cromatina
/
Conformação de Ácido Nucleico
Limite:
Animals
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
1988
Tipo de documento:
Article