Summary information and primary citation
- PDB-id
-
5ink;
DSSR-derived features in text and
JSON formats; DNAproDB
- Class
- hydrolase-DNA
- Method
- X-ray (2.15 Å)
- Summary
- Mouse tdp2 reaction product (5'-phosphorylated
DNA)-abasic-thf-mg2+ complex
- Reference
-
Schellenberg MJ, Perera L, Strom CN, Waters CA, Monian B,
Appel CD, Vilas CK, Williams JG, Ramsden DA, Williams RS
(2016): "Reversal
of DNA damage induced Topoisomerase 2 DNA-protein
crosslinks by Tdp2." Nucleic Acids Res.,
44, 3829-3844. doi: 10.1093/nar/gkw228.
- Abstract
- Mammalian Tyrosyl-DNA phosphodiesterase 2 (Tdp2)
reverses Topoisomerase 2 (Top2) DNA-protein crosslinks
triggered by Top2 engagement of DNA damage or poisoning by
anticancer drugs. Tdp2 deficiencies are linked to
neurological disease and cellular sensitivity to Top2
poisons. Herein, we report X-ray crystal structures of
ligand-free Tdp2 and Tdp2-DNA complexes with alkylated and
abasic DNA that unveil a dynamic Tdp2 active site lid and
deep substrate binding trench well-suited for engaging the
diverse DNA damage triggers of abortive Top2 reactions.
Modeling of a proposed Tdp2 reaction coordinate, combined
with mutagenesis and biochemical studies support a single
Mg(2+)-ion mechanism assisted by a phosphotyrosyl-arginine
cation-π interface. We further identify a Tdp2 active site
SNP that ablates Tdp2 Mg(2+) binding and catalytic
activity, impairs Tdp2 mediated NHEJ of tyrosine blocked
termini, and renders cells sensitive to the anticancer
agent etoposide. Collectively, our results provide a
structural mechanism for Tdp2 engagement of heterogeneous
DNA damage that causes Top2 poisoning, and indicate that
evaluation of Tdp2 status may be an important personalized
medicine biomarker informing on individual sensitivities to
chemotherapeutic Top2 poisons.
