Structural insight into dynamic bypass of the major cisplatin-DNA adduct by Y-family polymerase Dpo4

Journal Article · Mon Aug 23 04:00:00 EDT 2010 · EMBO J.

DOI:https://doi.org/10.1038/emboj.2010.101· OSTI ID:1002463

Wong, Jimson H.Y.; Brown, Jessica A; Suo, Zucai; Blum, Paul; Nohmi, Takehiko; Ling, Hong ^[1]

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1. OSU

Y-family DNA polymerases bypass Pt-GG, the cisplatin-DNA double-base lesion, contributing to the cisplatin resistance in tumour cells. To reveal the mechanism, we determined three structures of the Y-family DNA polymerase, Dpo4, in complex with Pt-GG DNA. The crystallographic snapshots show three stages of lesion bypass: the nucleotide insertions opposite the 3{prime}G (first insertion) and 5{prime}G (second insertion) of Pt-GG, and the primer extension beyond the lesion site. We observed a dynamic process, in which the lesion was converted from an open and angular conformation at the first insertion to a depressed and nearly parallel conformation at the subsequent reaction stages to fit into the active site of Dpo4. The DNA translocation-coupled conformational change may account for additional inhibition on the second insertion reaction. The structures illustrate that Pt-GG disturbs the replicating base pair in the active site, which reduces the catalytic efficiency and fidelity. The in vivo relevance of Dpo4-mediated Pt-GG bypass was addressed by a dpo-4 knockout strain of Sulfolobus solfataricus, which exhibits enhanced sensitivity to cisplatin and proteomic alterations consistent with genomic stress.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1002463
• Journal Information: EMBO J., Journal Name: EMBO J. Journal Issue: (12) ; 05, 2010 Vol. 29; ISSN EMJODG; ISSN 0261-4189
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS
ADDUCTS
CONFORMATIONAL CHANGES
DNA
DNA POLYMERASES
EFFICIENCY
IN VIVO
NUCLEOTIDES
POLYMERASES
SENSITIVITY
STRAINS