Summary information and primary citation
- PDB-id
-
7u7v;
DSSR-derived features in text and
JSON formats
- Class
- transferase-DNA
- Method
- X-ray (1.65 Å)
- Summary
- Human DNA polymerase eta-DNA-dgmpnpp ternary mismatch
complex in 0.4 mm mg2+ for 600s
- Reference
-
Chang C, Lee Luo C, Gao Y (2022): "In
crystallo observation of three metal ion promoted DNA
polymerase misincorporation." Nat Commun,
13, 2346. doi: 10.1038/s41467-022-30005-3.
- Abstract
- Error-free replication of DNA is essential for life.
Despite the proofreading capability of several polymerases,
intrinsic polymerase fidelity is in general much higher
than what base-pairing energies can provide. Although
researchers have investigated this long-standing question
with kinetics, structural determination, and computational
simulations, the structural factors that dictate polymerase
fidelity are not fully resolved. Time-resolved
crystallography has elucidated correct nucleotide
incorporation and established a three-metal-ion-dependent
catalytic mechanism for polymerases. Using X-ray
time-resolved crystallography, we visualize the complete
DNA misincorporation process catalyzed by DNA polymerase η.
The resulting molecular snapshots suggest primer 3´-OH
alignment mediated by A-site metal ion binding is the key
step in substrate discrimination. Moreover, we observe that
C-site metal ion binding preceded the nucleotidyl transfer
reaction and demonstrate that the C-site metal ion is
strictly required for misincorporation. Our results
highlight the essential but separate roles of the three
metal ions in DNA synthesis.
