Ensuring error-free DNA repair

Mammalian mismatch repair: error-free or error-prone?

A considerable surge of interest in the mismatch repair (MMR) system has been brought about by the discovery of a link between Lynch syndrome, an inherited predisposition to cancer of the colon and other organs, and malfunction of this key DNA metabolic pathway. This review focuses on recent advances in our understanding of the molecular mechanisms of canonical MMR, which improves replication f...

Imperfect DNA Repair and the Error Catastrophe

In this Letter, we extend the semiconservative quasispecies equations to incorporate imperfect DNA lesion repair. We study the equilibrium behavior of this model in the limit of infinite sequence length and population size, using a single-fitness-peak landscape for which the master genome can sustain a finite number of lesions and remain viable. We provide a full analytical treatment of the pro...

Mismatch repair participates in error-free processing of DNA interstrand crosslinks in human cells.

DNA interstrand crosslinks (ICLs) present formidable blocks to DNA metabolic processes and must be repaired for cell survival. ICLs are induced in DNA by intercalating compounds such as the widely used therapeutic agent psoralen. In bacteria, both nucleotide excision repair (NER) and homologous recombination are required for the repair of ICLs. The processing of ICLs in mammalian cells is not c...

Ring-like nucleoids and DNA repair through error-free nonhomologous end joining in Deinococcus radiodurans.

Mutagenic DNA repair in Escherichia coli: conditions for error-free filling of daughter strand gaps.

Two situations have been observed in which daughter strand gaps in DNA synthesized after exposure of excision-deficient Escherichia coli to ultraviolet light are filled but in which no mutations are formed as judged by loss of photoreversibility: (i) during the first 20 min of growth after u.v. irradiation, and (ii) when repair is allowed to occur in buffer. We suggest as an explanation that th...