Excision repair

Excision repair is a term applied to several DNA repair mechanisms. They remove the damaged nucleotides and are able to determine the correct sequence from the complementary strand of DNA.

Specific mechanisms include:

Base excision repair (BER), which repairs damage due to a single nucleotide caused by oxidation, alkylation, hydrolysis, or deamination;
Nucleotide excision repair (NER), which repairs damage affecting 2−30 nucleotide-length strands. These include bulky, helix distorting damage, such as thymine dimerization and other types of cyclobutyl dimerization caused by UV light as well as single-strand breaks. A specialized form of NER known as Transcription-Coupled Repair (TCR) deploys high-priority NER repair enzymes to genes that are being actively transcribed;
Mismatch repair (MMR), which corrects errors of DNA replication and recombination that result in mispaired nucleotides.

DNA repair

Excision repair	Base excision repair/AP site (DNA glycosylase, Uracil-DNA glycosylase, Poly ADP ribose polymerase) • Nucleotide excision repair/ERCC (XPA, XPB, XPC, XPD/ERCC2, XPE/DDB1, XPF/DDB1, XPG/ERCC5, ERCC1, RPA, RAD23A, RAD23B, Excinuclease)

Other forms of repair	Transcription-coupled repair (ERCC6, ERCC8) • DNA mismatch repair (MLH1, MSH2) • Homology directed repair • Non-homologous end joining (Ku) • Microhomology-mediated end joining • Postreplication repair • Photolyase (CRY1, CRY2)

Other/ungrouped proteins	Ogt • PcrA • Proliferating Cell Nuclear Antigen • Homologous recombination (RecA • Sgs1 • Slx4)

Regulation	SOS box • SOS response

Other/ungrouped	8-Oxoguanine • Adaptive response • Meiotic recombination checkpoint • RecF pathway DNA helicase: BLM · WRN FANC proteins: core protein complex (FANCA, FANCB, FANCC, FANCE, FANCF, FANCG, FANCL, FANCM), FANCD1, FANCD2, FANCI, FANCJ, FANCN

see also DNA repair-deficiency disorder B bsyn: dna (repl, cycl, reco, repr) · tscr (fact, tcrg, nucl, rnat, rept, ptts) · tltn (risu, pttl, nexn) · dnab, rnab/runp · stru (domn, 1°, 2°, 3°, 4°)