Pathway · 5 proteins
Homologous recombination
Proteins of this group that KEGG places on its “Homologous recombination” map for Aquifex aeolicus.
How it works
This map covers repair of broken DNA by copying from an intact second copy, and the restart of stalled copying. The proteins here coat single-stranded DNA, cut back broken ends, unwind DNA and help restart replication forks.
Grouped by KEGG pathway map. The explanation above is the atlas’s own; the map itself covers more organisms than Aquifex.
Its proteins
| Protein | EC | Reaction (UniProt) | Metal or cluster | Amino acids | Certainty |
|---|---|---|---|---|---|
| Single-stranded DNA-binding protein | — | — | — | 147 | Step named |
| Probable DNA double-strand break repair Rad50 ATPase | — | — | Zn(2+) | 978 | Step named |
| Nuclease SbcCD subunit D | — | — | — | 379 | Step named |
| Single-stranded-DNA-specific exonuclease RecJ | — | — | — | 538 | Step named |
| DNA repair protein RecN | — | — | — | 520 | Step named |
Origins
How could broken DNA be repaired before recombination proteins existed?
RecA-like recombinases are found across all domains of life.
A break across both strands can be repaired accurately only by copying the missing information from a second, intact copy. That needs a protein that finds the matching sequence and exchanges strands, and five proteins in this pathway serve it.
From the books: Ribas de Pouplana (ed.), The Genetic Code and the Origin of Life, p. 158.
The wider question for this part of the cell: origins for copying and repairing the genome.
Sources
- KEGG map aae03440 (enzymes of this organism highlighted)
Other pathways in this group: DNA damage repair · DNA synthesis · Topology management · Joining and end processing · Recombination and restart · Chromosome preparation · Initiation and opening · Base excision repair · Cysteine and methionine metabolism · Not yet placed in a pathway