An Archaeal Homolog of Proteasome Assembly Factor Functions as a Proteasome Activator (original) (raw)
Figure 4
PbaB tetramer caps the heptameric α subunit ring of the 20S proteasome.
Class averages of the PbaB-20S proteasome complexes; (A) the 20S proteasome doubly capped with PbaB on both sides, (B) and (C) the 20S proteasome singly capped with PbaB on one side. Scale bar indicates 10 nm. Three-dimensional tomograms for the PbaB-20S proteasome complexes were obtained by the negative staining electron tomography; (D) parallel cap (n = 9), (E) tilted cap (n = 42). Seven-fold symmetrical operation is applied to the 20S proteasome part.