5MSK

Mouse PA28beta

5MSK の概要

• エントリーDOI: 10.2210/pdb5msk/pdb
• 分子名称: Proteasome activator complex subunit 2 (1 entity in total)
• 機能のキーワード: heptamer, regbeta, interferon-gamma, hydrolase, structural protein
• 由来する生物種: Mus musculus (Mouse)
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 189659.98

構造登録者

Huber, E.M.,Groll, M. (登録日: 2017-01-05, 公開日: 2017-09-13, 最終更新日: 2024-01-17)

主引用文献

Huber, E.M.,Groll, M.
The Mammalian Proteasome Activator PA28 Forms an Asymmetric alpha 4 beta 3 Complex.
Structure, 25:1473-1480.e3, 2017

PubMed Abstract: The heptameric proteasome activator (PA) 28αβ is known to modulate class I antigen processing by docking onto 20S proteasome core particles (CPs). The exact stoichiometry and arrangement of its α and β subunits, however, is still controversial. Here we analyzed murine PA28 complexes regarding structure and assembly. Strikingly, PA28α, PA28β, and PA28αβ preparations form heptamers, but solely PA28α and PA28αβ associate with CPs. Co-expression of α and β yields one unique PA28αβ species with an unchangeable subunit composition. Structural data on PA28α, PA28β, and PA28αβ up to 2.9 Å resolution reveal a PA28αβ complex with an alternating subunit arrangement and a single α-α interface. Differential scanning fluorimetry experiments and activity assays classify PA28αβ as most stable and most active, indicating that this assembly might represent the physiologically relevant species. Together, our data resolve subunit composition and arrangement of PA28αβ and clarify how an asymmetric heptamer can be assembled from two highly homologous subunits.

PubMed: 28867616
DOI: 10.1016/j.str.2017.07.013

実験手法

X-RAY DIFFRACTION (3.6 Å)