Extended Data Fig. 1: Structural characterization of USP1-UAF1.

a, SEC-SAXS trace for the crystallized ubiquitin-bound USP1-UAF1 construct. b, Guinier plot of buffer subtracted, averaged SAXS measurements. c, Fit of different USP-UAF1 crystal structures to SAXS measurements. The better resolved chains A and B of the ubiquitin-free (USP1-UAF1) and chains A, B, and C (USP1^Ub-UAF1) of the ubiquitin-bound structure were used for fitting. d, The two USP1-UAF1 complexes in the asymmetric unit of the ubiquitin-free (brown) and ubiquitin-bound (blue) crystal structures aligned by UAF1. e, A phenylalanine, conserved in USP1, USP12, and USP46, occupies a pocket between the palm and fingers in ubiquitin-free USP1-UAF1 structure, and in USP46-UAF1-WDR20 (PDB 6JLQ)²⁶ and USP12-UAF1-WDR20 (PDB 5K1C) but not USP12-UAF1 (PDB 5K1A)²³. f, The BL1 is ordered in ubiquitin-free USP1-UAF1 structure, and in USP46-UAF1-WDR20 (PDB 6JLQ)²⁶ and USP12-UAF1-WDR20 (PDB 5K1C) but not USP12-UAF1 (PDB 5K1A)²³. g, Multiple sequence alignment of USP1, USP12, and USP46 in the region including the conserved phenylalanine (indicated by *) and the BL1. Sequence alignment was performed using Clustal Omega (http://www.ebi.ac.uk/Tools/msa/clustalo/) and visualized using BOXSHADE.