3wz2

Publication Abstract from PubMed

Formation of the eukaryotic proteasome is not a spontaneous process but a highly ordered process assisted by several assembly chaperones. In contrast, archaeal proteasome subunits can spontaneously assemble into an active form. Recent bioinformatic analysis identified the proteasome-assembly chaperone-like proteins, PbaA and PbaB, in archaea. Our previous study showed that the PbaB homotetramer functions as a proteasome activator through its tentacle-like C-terminal segments. However, a functional role of the other homolog PbaA has remained elusive. Here we determined the 2.25-A resolution structure of PbaA, illustrating its disparate tertiary and quaternary structures compared with PbaB. PbaA forms a homopentamer in which the C-terminal segments, with a putative proteasome-activating motif, are packed against the core. These findings offer deeper insights into the molecular evolution relationships between the proteasome-assembly chaperones and the proteasome activators.

Crystal structure of archaeal homolog of proteasome-assembly chaperone PbaA.,Sikdar A, Satoh T, Kawasaki M, Kato K Biochem Biophys Res Commun. 2014 Oct 5. pii: S0006-291X(14)01751-3. doi:, 10.1016/j.bbrc.2014.09.114. PMID:25285636^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.