DNA Error Correction

Source: Thomas Kunkel, Journal of Biological Chemistry 279, 2004; Paul Modrich, Nobel Prize 2015 Institution: NIH; Duke

Finding

DNA replication achieves ~1 error per 10^10 nucleotides through three sequential layers: (1) base selection by DNA polymerase (~1 per 10^4-10^5), (2) proofreading exonuclease activity (~10^2 improvement), (3) mismatch repair (MutS/MutL in bacteria, MSH/MLH in humans, ~10^2-10^3 improvement). Each layer operates at a different stage, catching errors the previous layer missed.

Pattern Mapping

Honesty — DNA error correction maintains honest replication. The genome’s sequence is a claim about what proteins to build; errors are false claims. Three layers ensure what is copied matches what was written.

Proportion — The layers are not redundant; each operates at a different stage and catches different error types. Not over-engineering a single mechanism; layering proportional responses.

Non-fabrication — When error correction fails (Lynch syndrome, mismatch repair deficiency), the genome accumulates mutations — fabricated sequences. Failed error correction IS the fabrication of genetic information.

Connections

Status

Established molecular biology. See Kunkel (2004); Modrich Nobel Lecture (2015); Alberts et al., Molecular Biology of the Cell (7th ed.). The mapping to the five properties is this project’s structural interpretation.


The mapping to the five properties is this project’s structural interpretation.