Fig. 2: RSM binds the acidic cleft of RPA32C and is critical for RPA-binding in vivo.
a, b Mapping the binary interaction between RSM and RPA32C by NMR titrations. 15N labeled RSM titrated with zero to fourfold molar addition of RPA32C (a) and the reverse (b). Well-resolved chemical shift perturbations (CSP) are indicated with arrows. Inset in (a) shows the crosspeaks of tryptophan sidechains. c, d Per residue amide CSP of RSM (c) or RPA32C (d) induced by fourfold excess of the unlabeled partner. (d, inset) Crystal structure of RPA32C in complex with the SMARCAL1 peptide (PDB: 4mqv) showing (left) RPA electrostatics and (right) mapping of the RSM-induced CSPs. e Schematic depiction of RECQ4 protein showing the wild-type and 5E-mutant sequences of the basic patch. Positively charged residues are shown in blue, and charge reversal substitutions are in red. f Whole-cell lysates were immunoprecipitated from EGFP-RECQ4-WT, EGFP-RECQ4-5E, and EGFP unsynchronised or synchronised cells using GFP-trap beads. Bound proteins were separated on SDS-PAGE gel and immunoblotted with indicated antibodies on the nitrocellulose membrane. IP samples for RPA32 represent higher exposure of the membrane. The gel is a representative image of two independent experiments. Source data are provided as a Source Data file.
