Recognition of DNA Interstrand Cross-link of Antitumor Cisplatin by HMGB1 Protein
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- 作者：Jana Kasparkova ; Olivier Delalande ; Michal Stros ; Miguel-Angel Elizondo-Riojas ; Marie Vojtiskova ; Jiri Kozelka ; and Viktor Brabec
- 刊名：Biochemistry
- 出版年：2003
- 出版时间：February 11, 2003
- 年：2003
- 卷：42
- 期：5
- 页码：1234 - 1244
- 全文大小：386K
- 年卷期：v.42,no.5(February 11, 2003)
- ISSN：1520-4995
文摘
Several proteins that specifically bind to DNA modified by cisplatin, including those containingHMG-domains, mediate antitumor activity of this drug. Oligodeoxyribonucleotide duplexes containing asingle, site-specific interstrand cross-link of cisplatin were probed for recognition by the rat chromosomalprotein HMGB1 and its domains A and B using the electrophoretic mobility-shift assay. It has beenfound that the full-length HMGB1 protein and its domain B to which the lysine-rich region (seven aminoacid residues) of the A/B linker is attached at the N-terminus (the domain HMGB1b7) specifically recognizeDNA interstrand cross-linked by cisplatin. The affinity of these proteins to the interstrand cross-link ofcisplatin is not very different from that to the major 1,2-GG intrastrand cross-link of this drug. In contrast,no recognition of the interstrand cross-link by the domain B lacking this region or by the domain A withor without this lysine-rich region attached to its C-terminus is noticed under conditions when these proteinsreadily bind to 1,2-GG intrastrand adduct. A structural model for the complex formed between theinterstrand cross-linked DNA and the domain HMGB1b7 was constructed and refined using molecularmechanics and molecular dynamics techniques. The calculated accessible areas around the deoxyriboseprotons correlate well with the experimental hydroxyl radical footprint. The model suggests that the onlymajor adaptation necessary for obtaining excellent surface complementarity is extra DNA unwinding (~40
)at the site of the cross-link. The model structure is consistent with the hypothesis that the enhancementof binding affinity afforded by the basic lysine-rich A/B linker is a consequence of its tight binding to thesugar-phosphate backbone of both DNA strands.
)at the site of the cross-link. The model structure is consistent with the hypothesis that the enhancementof binding affinity afforded by the basic lysine-rich A/B linker is a consequence of its tight binding to thesugar-phosphate backbone of both DNA strands.