Fig. 5: Survey of C-degrons targeted by the SCF^Das1 ubiquitin ligase.

a Workflow to identify C-degrons targeted by SCF^Das1. The tFT-X₁₂ degron library consists of 4709 putative degrons from the tFT-X₁₂ library and 274 stable peptides as controls (Supplementary Data 5). b–d MPS profiling of the tFT-X₁₂ degron library in wild type and doa10Δ backgrounds. Constructs stabilized (s), partially stabilized (p) or not affected (n) in the doa10Δ mutant. b Scatter plot of PSIs, excluding stable controls. R1 to R5, putative Doa10 degrons with a terminal arginine. c, Hydrophobicity of the Doa10-dependent constructs. Number of peptides in each group is indicated. Centerlines mark the medians, box limits indicate the 25th and 75th percentiles, and whiskers extend to the minimum and maximum value in each group. *p = 0.012, **p = 4 × 10⁻¹⁰ in a one-sided Mann-Whitney U-test. d Relative amino acid frequency in Doa10-dependent constructs, normalized to the relative frequency in the tFT-X₁₂ library (Fig. 1c). Amino acids absent per position in Doa10-dependent constructs are marked with black circles. e PSIs in the tFT-X₁₂ degron library, excluding stable controls, determined by MPS profiling in das1Δ and cdc53-1 backgrounds. f–h MPS profiling of the tFT-X₁₂ degron library in wild type and das1Δ backgrounds. Constructs stabilized (s), partially stabilized (p) or not affected (n) in the das1Δ mutant. f Scatter plot of PSIs, excluding stable controls. W1 to W3, putative Das1 degrons with a tryptophan at position −5. g Hydrophobicity of the Das1-dependent constructs. Number of peptides in each group is indicated. Centerlines mark the medians, box limits indicate the 25th and 75th percentiles, and whiskers extend to the minimum and maximum value in each group. ***p < 2.2 × 10⁻¹⁶ in a one-sided Mann-Whitney U-test. h Relative amino acid frequency in Das1-dependent constructs, normalized to the relative frequency in the tFT-X₁₂ library (Fig. 1c). Amino acids absent per position in Das1-dependent constructs are marked with black circles. i, j Heatmaps of PSIs determined by MPS profiling. Impact of extending the C-terminus by a single amino acid ( + 1 position) (i) and saturation mutagenesis (j) of tFT-W1, tFT-W2 and tFT-W3 constructs from f. k Model of substrate recognition by SCF^Das1 via C-degrons (left) and potential C-degron motifs (right). Bottom, sequence logos for the five motifs, based on the 931 Das1 degrons from f. Number of peptides forming and unique to each logo are indicated. Source data are provided as a Source Data file.