title: Recognition of DNA interstrand cross-link of antitumor cisplatin by HMGB1 protein.
abstract: Several proteins that specifically bind to DNA modified by cisplatin, including those containing HMG-domains, mediate antitumor activity of this drug. Oligodeoxyribonucleotide duplexes containing a single, site-specific interstrand cross-link of cisplatin were probed for recognition by the rat chromosomal protein HMGB1 and its domains A and B using the electrophoretic mobility-shift assay. It has been found that the full-length HMGB1 protein and its domain B to which the lysine-rich region (seven amino acid residues) of the A/B linker is attached at the N-terminus (the domain HMGB1b7) specifically recognize DNA interstrand cross-linked by cisplatin. The affinity of these proteins to the interstrand cross-link of cisplatin 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 with or without this lysine-rich region attached to its C-terminus is noticed under conditions when these proteins readily bind to 1,2-GG intrastrand adduct. A structural model for the complex formed between the interstrand cross-linked DNA and the domain HMGB1b7 was constructed and refined using molecular mechanics and molecular dynamics techniques. The calculated accessible areas around the deoxyribose protons correlate well with the experimental hydroxyl radical footprint. The model suggests that the only major adaptation necessary for obtaining excellent surface complementarity is extra DNA unwinding (approximately 40 degrees ) at the site of the cross-link. The model structure is consistent with the hypothesis that the enhancement of binding affinity afforded by the basic lysine-rich A/B linker is a consequence of its tight binding to the sugar-phosphate backbone of both DNA strands.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, CZ-61265 Brno, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Kasparkova
authors.forename: Olivier
authors.initials: O
authors.lastname: Delalande
authors.forename: Michal
authors.initials: M
authors.lastname: Stros
authors.forename: Miguel-Angel
authors.initials: MA
authors.lastname: Elizondo-Riojas
authors.forename: Marie
authors.initials: M
authors.lastname: Vojtiskova
authors.forename: Jiri
authors.initials: J
authors.lastname: Kozelka
authors.forename: Viktor
authors.initials: V
authors.lastname: Brabec
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry*; D020029:Base Pairing; D002945:Cisplatin / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D018736:DNA Adducts / Q000737:chemistry*; D003855:Deoxyribose / Q000737:chemistry; D024243:HMGB1 Protein / Q000737:chemistry* / Q000302:isolation & purification; D006860:Hydrogen Bonding; D017665:Hydroxyl Radical / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry; D011485:Protein Binding; D023302:Protein Footprinting; D017434:Protein Structure, Tertiary; D011522:Protons; D051381:Rats; D012997:Solvents; D013499:Surface Properties
chemical_list: D000596:Amino Acids; D000970:Antineoplastic Agents; D003432:Cross-Linking Reagents; D018736:DNA Adducts; D024243:HMGB1 Protein; D009692:Nucleic Acid Heteroduplexes; D010446:Peptide Fragments; D011522:Protons; D012997:Solvents; D017665:Hydroxyl Radical; D003855:Deoxyribose; D008239:Lysine; D002945:Cisplatin