Backbone NMR Assignments of FN1 Protein

¹H–¹⁵N HSQC, HNCA, HNCO, HN(CA)CO, HN(CO)CA, HNCACB, and CBCACONH spectra for FN1 backbone assignments were recorded at 25 °C on a Bruker 600 MHz DRX spectrometer equipped with a 5 mm inverse cryogenic probe. NMR spectra for HSQC titrations were recorded on a Bruker 900 MHz AVANCE spectrometer equipped with a 5 mm TCI cryogenic probe. Samples for all the NMR experiments were in a buffer containing 300 mM NaCl and 20 mM KH₂PO₄ (pH 6.6), supplemented with 10% D₂O. Backbone dihedral angles and the secondary structure of FN1 were predicted using Talos+.^{41 (link)} All NMR data were processed using NMRPipe^{42 (link)} and analyzed using UCSF Sparky. HSQC titrations were recorded in a 5 mm NMR tube at 1:0 (8 scans), 1:5 (32 scans), and 1:10 (64 scans) ratios of FN1 to 6xHis-SUMO-PBR and its mutant (R82A/R93A).