Fig. 2: Structural basis of K11/K48-branched Ub chain recognition by the human 26S proteasome.
From: Structural basis of K11/K48-branched ubiquitin chain recognition by the human 26S proteasome
Cryo-EM structures of the 19S RP in the EB:Ub4 state (a) and substrate-processing ED:Ub4 state (b) bound with the K11/K48-branched Ub4 with the same coloring scheme as in Fig. 1e. The expanded views of the individual Ubs in the two functional states are shown on the right panels with the individual Ub shown in cartoon representations and the proteasomal proteins in surface representations. The identities of the interacting residues in Ub are labeled in black. The identities of the proteasomal residues involved in forming salt bridges and/or hydrogen bonds with Ubs are indicated with matching colors according to the scheme shown on the left panels. Circled insets on the upper left corners of individual Ub panels illustrate the Ub binding interfaces outlined by black lines. The I44, I36 and D58 patches on the Ubs are colored hot pink, blue and brown, respectively. Proteasomal residues involved in contacting the I44, I36 and D58 patches are colored in the same way.
