<p>Purified soluble Ure2p (1 μg) was incubated without or with purified 26S proteasome (0.4 μg) in the presence of 2.5 mM ATP at 30°C under mild agitation (<300 rpm) for 0, 1, 2 or 3 h. Peptides produced during the incubation were identified by nanoLC-LTQ-Orbitrap mass spectrometry (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131789#pone.0131789.s001" target="_blank">S1 Table</a>). These peptides were not produced when Ure2p was incubated alone (data not shown). The color code reflects the time point at which each individual peptide was first detected, as indicated. <b>(Inset)</b> Aliquots from the reaction mixes were analyzed by SDS-PAGE and Western blot using anti-Ure2p antibodies.</p
