Table 3.
Oligomeric structures formed by single-strand annealing proteins in their different DNA-bound states.a
| Protein name (organism) | Oligomer without DNA | Oligomer on ssDNA | Oligomer on dsDNA (annealed duplex) | Method and References |
|---|---|---|---|---|
| Erf (P22 phage) | 10–14-mer rings | large aggregates | large aggregates | nsTEM; Poteete et al. (1983) |
| RecT (Rac prophage) | 7–8-mer rings | twisted filaments | inter-twined filaments | nsTEM; Thresher et al. (1995) |
| Redβ (phage λ) | 12-mer rings | 15–18-mer rings | left-handed helical filaments | nsTEM; Passy et al. (1999) |
| Redβ (phage λ) | 11-mer split lock washer | disperse monomers | left-handed helical filaments | AFM; Erler et al. (2009) |
| G35P (B. subtilis phage SPP1) | 7–8-mer rings | left-handed helical filaments | nsTEM; Ayora et al. (2002) | |
| hRad52 (human) | 7-mer ring | nsTEM/STEM; Stasiak et al. (2000) | ||
| hRad52 DNA-binding domain | 11-mer rings | XRAY; Singleton et al. (2002); Kagawa et al. (2002) | ||
| hRad52 DNA-binding domain | 11-mer ring, networks of rings | XRAY; Saotome et al. (2018) | ||
| SAK (L. lactis phage ul36) | 11-mer rings, stacks of rings | nsTEM; Ploquin et al. (2008) | ||
| Mgm101 (mitochondrial) | 14-mer rings, compressed filaments | distinct nucleoprotein filaments | nsTEM; Mbantenkhu et al. (2011) | |
| ICP8 (HSV-1) | Bipolar filaments | nsTEM; Makhov et al. (2009) | ||
| ICP8 (HSV-1) | 2 stacked 9-mer rings | nsTEM; Tolun et al. (2013) | ||
| DdrB (D. radiodurans) | 5-mer ring, higher-ordered assemblies | 5-mer ring (with partially annealed intermediate) | XRAY; Sugiman-Marangos et al. (2013), 2016 | |
| RecO (D. radiodurans) | monomer | XRAY; Makharashvili et al. (2004); Leiros et al. (2005) |
a
The table lists several SSAPs and the oligomeric states that they are seen to occur in the different DNA-bound states, by different experimental methods. The table includes four distinct families of SSAPs, which all have distinct folds. The Rad52 family includes Rad52, the phage annealing proteins (RecT, Redβ, G35P, SAK), and the mitochondrial annealing protein Mgm101. The ICP8 family includes the annealing proteins from oncogenic dsDNA virsus (HSV1, KSHV, EBV, etc.). DdrB and RecO each have distinct folds of their own.