Table 1.
Exonucleases discussed in this article
| Exonuclease | Polarity | Metabolic pathway | References |
|---|---|---|---|
| Polymerase δ, ε, γ | 3′-5′ | Replication (proofreading) | Hubscher et al. 2002; Tran et al. 1999; Longley et al. 2001 |
| ExoN | 3′-5′ | Unknown—proofreading? | Brown et al. 2002 |
| TREX1/TREX2 | 3′-5′ | Aberrant ssDNA removal/proofreading? | Chen et al. 2007; Yang et al. 2007 |
| p53 | 3′-5′ | Multiple; proofreading? | Mummenbrauer et al. 1996 |
| APE1/APE2a | 3′-5′ | BER, replication | Wilson 2003; Burkovics et al. 2006 |
| FEN1a | 5′-3′ | Okazaki fragment processing, BER | Harrington and Lieber, 1994 |
| XPG/ERCC5 | 5′-3′ | NER; transcription stabilisation | Habraken et al. 1994a, b |
| EXO1a | 5′-3′ | Multiple: MMR, DSBR, meiosis | Fiorentini et al. 1997; Lee and Wilson 1999; Tishkoff et al. 1998; Tsubouchi and Ogawa 2000 |
| WRNb | 3′-5′ | Multiple: DNA repair, telomeres | Cooper et al. 2000; Huang et al. 1998, 2000 |
| Dna2 | 3′-5′ | Replication—Okazaki fragment processing | Reviewed in Budd et al. (2009) |
| MRE11c/RAD50/NBS1 | 3′-5′ | DSBR; replication restart | Buis et al. 2008; D'Amours and Jackson 2002 |
| hRAD9 | 3′-5′ | Checkpoint | Bessho and Sancar 2000; Parker et al. 1998 |
| EXDL2 | 3′-5′d | Unknown—ICLR? | Smogorzewska et al. 2010 |
| FAN1 | 5′-3′ | ICLR? | Kratz et al. 2010; MacKay et al. 2010; Smogorzewska et al. 2010 |
| EXOGa | 5′-3′ | Multiple in mitochondria | Cymerman et al. 2008 |
BER base excision repair, DSBR double-strand DNA break repair, MMR mismatch repair, ICLR interstrand crosslink repair
aEXO1 also has (flap) endonucleolytic activity and 3′-5′ polarity, whilst the major activities of FEN1 and APE1 are as Flap endonucleases. EXOG also has endonucleolytic activity
bWRN has 3′-5′ exonuclease and a reported 5′-3′ activity in conjunction with Ku70/86
cMRE11 contains the exonuclease activity
dEXDL2 exonuclease activity is assumed by homology