Fig. 3: Rpa2^WH connects RPA to the archaeal replicative DNA polymerases.

a–h Biolayer Interferometry (BLI) results for (a) specific binding of immobilized histidine-tagged PriSL at 50 nM to 10 µM wild-type RPA (teal) and to 10 µM RPA^ΔWH (purple); b specific binding of immobilized biotin-tagged nucleoprotein RPA filaments to 12.5 nM PriSL (teal) and immobilized biotin-tagged nucleoprotein RPA^ΔWH filaments to 12.5 nM PriSL (purple); c specific binding of immobilized histidine-tagged PolD at 50 nM to 1 µM wild-type RPA (teal) and to 1 µM RPA^ΔWH (purple); d specific binding of immobilized biotin-tagged nucleoprotein RPA filaments to 250 nM PolD (teal) and immobilized biotin-tagged nucleoprotein RPA^ΔWH filaments to 250 nM PolD (purple). e Specific binding of PriSL (500, 250, 125, 62.5, 31.25, 15.62, 7.81 nM, n = 3) to immobilized histidine-tagged Rpa2 C-terminal winged-domain. f Specific binding of PriSL (100, 50, 25, 12.5, 6.25, 3.12, 1.56 nM, n = 3 biological replicates) to immobilized biotin-tagged nucleoprotein RPA filaments. g Specific binding of PolD (1000, 500, 250, 125, 62.5, 31.25, 15.62 nM, n = 3 biological replicates) to immobilized histidine-tagged Rpa2^WH. h Specific binding of PolD (1000, 500, 250, 125, 62.5, 31.25, 15.62 nM, n = 3) to immobilized biotin-tagged nucleoprotein RPA filaments. Steady-state analyses were performed using the average signal measured at the end of the association steps. Data are represented as mean value ± standard deviations (error bars). Raw data are provided in the source data file. i–l Identification of the Rpa2^WH binding surface to the DNA polymerases by NMR. i, j NMR chemical shift perturbations (CSP) and peak intensity ratios I_cplx/I_free (log₁₀ scale) on Rpa2^WH induced by PriSL^ΔCTD and PolD, respectively. The dotted blue and red lines correspond to I_cplx/I_free ratios of 0.4 and 0.25 for the complex with PriSL^ΔCTD and 0.4 and 0.17 for the complex with PolD, as used for the color coding in (k, l). Error bars in the I_cplx/I_free histograms represent the noise standard deviation in the spectra (see section “Methods”). For clarity, the most affected regions in terms of CSP and/or intensity ratio are highlighted by light red boxes. Secondary structure elements are indicated at the top. k, l Mapping of the intensity ratio I_cplx/I_free on Rpa2^WH color coded from black (no attenuation), blue (weak attenuation) to red (large attenuation) as indicated. Residues in gray denote missing data (proline or overlapping signals). The unfolded residues 200-205 that transiently contact PriSL^ΔCTD are highlighted in light violet. The residues that are most severely affected by the binding (I_cplx/I_free < 0.29 for PriSL^ΔCTD and <0.26 for PolD) are depicted as transparent spheres and delineate the respective binding surfaces to the polymerases.