Extended Data Fig. 1: Ubr1-mediated Lys48-linked polyubiquitination of degron peptides.
From: Structural insights into Ubr1-mediated N-degron polyubiquitination
a, The amino acid sequence of the degron peptide (Degron). SPPS: solid-phase peptide synthesis. b, The synthetic route of the monoubiquitinated degron peptide (Ub-Degron). c–d, Fluorescent labelling of Degron (c) and Ub-Degron (d). An additional C-terminal cysteine was introduced for the labelling of fluorescein-5-maleimide. e, In vitro Ubr1-dependent ubiquitination assays using fluorescent Degron (top) and Ub-Degron (bottom) as substrates. Gel images are representative of independent biological replicates (n = 2). f–g, Quantitative evaluations of the kinetics of Ubr1-mediated ubiquitination initiation (f) and the first step of elongation (g). Averages of two independent experiments were plotted and fitted to the Michaelis–Menten model to estimate the Km and Kcat. Gel images are representative of independent biological replicates (n = 2).
