Fig. 3: TXNL1 specifically interacts with PS 26S proteasomes.
From: Structural landscape of the degrading 26S proteasome reveals conformation-specific binding of TXNL1
a, Proteasome binding and dissociation of N-terminally FAM-labeled TXNL1 (50 nM) was measured by changes in FP after incubation with human 26S proteasome (500 nM) in the absence or presence of FAT10 substrate (10 μM) and the NUB1 cofactor (12 μM). b, Time-resolved cryo-EM of actively degrading proteasomes with substoichiometric amounts of TXNL1 reveals TXNL1’s binding preference for PSs. Left: EM density of the proteasome in the PSRpt5 conformation shows partial occupancy with TXNL1’s PITH domain (orange). Right: zoomed-in views of example density maps from particles that were sorted into TXNL1-bound (top) and TXNL1-unbound (bottom) after local 3D classification and refinement of the PITH domain density. c, Fractions of proteasome particles with and without bound TXNL1 as a function of the PS conformation. KM, Michealis constant.
