Figure 5: The domain architectures of UvrB, UvrA, and TRCF. (a) UvrB is comprised of five domains. Domains 1a (yellow) and 3 (red) contain helicase motifs. Domain 1b (green) has the flexible 𝛽 -hairpin invosved in substrate recognition. Domain 2 (blue) interacts with UvrA. Domain 4 is disordered in the crystal structures. (b) UvrA is comprised of six domains: ATP-binding I (red), ATP-binding II (blue), signature I (pink), signature II (cyan), UvrB-binding (yellow), and insertion (green) domain. The white region is the other subunit of the dimer. (c) TRCF is comprised of seven domains. Domains 1 and 2 (not separated in the figure) comprise UvrB homology module (blue). Domains 5 (yellow) and 6 (green) comprise DNA translocation module. Relay helix (yellow) interacts with domain 4 (pink), RNA polymerase interaction domain (RID). The functions of domain 3 (orange) and domain 7 (red) are unclear.