Summary information and primary citation
- PDB-id
-
1nk4;
DSSR-derived features in text and
JSON formats
- Class
- transferase-DNA
- Method
- X-ray (1.6 Å)
- Summary
- Guanine-guanine mismatch at the polymerase active
site
- Reference
-
Johnson SJ, Beese LS (2004): "Structures
of mismatch replication errors observed in a DNA
polymerase." Cell(Cambridge,Mass.),
116, 803-816. doi: 10.1016/S0092-8674(04)00252-1.
- Abstract
- Accurate DNA replication is essential for genomic
stability. One mechanism by which high-fidelity DNA
polymerases maintain replication accuracy involves stalling
of the polymerase in response to covalent incorporation of
mismatched base pairs, thereby favoring subsequent mismatch
excision. Some polymerases retain a "short-term memory" of
replication errors, responding to mismatches up to four
base pairs in from the primer terminus. Here we a present a
structural characterization of all 12 possible mismatches
captured at the growing primer terminus in the active site
of a polymerase. Our observations suggest four mechanisms
that lead to mismatch-induced stalling of the polymerase.
Furthermore, we have observed the effects of extending a
mismatch up to six base pairs from the primer terminus and
find that long-range distortions in the DNA transmit the
presence of the mismatch back to the enzyme active site,
suggesting the structural basis for the short-term memory
of replication errors.
