Fig. 2: Structural basis for the DNA-binding activity by PabRPA.
From: DNA-binding mechanism and evolution of replication protein A
a Nucleic acid-binding specificity for PabRPA. Binding of PabRPA at 5 nM protein concentration on immobilized ssDNA-32mer, dsDNA-32mer, and ssRNA-32mer measured by surface plasmon resonance (SPR) (RU: resonance units). b Role of PabRPA subunits on ssDNA binding. Specific binding of Rpa1, Rpa2, or Rpa3 at 500 nM on immobilized ssDNA-32mer measured by SPR. c Specific binding of PabRPA full-length (5, 2.5, 1.25, 0.63, 0.31, 0.16 nM PabRPA; n = 2) or Tri-C (100, 50, 25, 12.5, 6.25, 3.2, 1.6 nM Tri-C; n = 3) to immobilized poly-dT35 ssDNA measured by biolayer interferometry (BLI). 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). Source data are provided as a source data file. d 3.2 Å crystal structure of the poly-dT20-bound Tri-C, with two focused views on Rpa1 OB-2 and Rpa2 OB-3 ssDNA-interacting residues.
