1PMA

PROTEASOME FROM THERMOPLASMA ACIDOPHILUM

Summary for 1PMA

• Entry DOI: 10.2210/pdb1pma/pdb
• Descriptor: PROTEASOME (2 entities in total)
• Functional Keywords: protease, proteasome, hydrolase
• Biological source: Thermoplasma acidophilum; More
• Cellular location: Cytoplasm (By similarity): P25156 P28061
• Total number of polymer chains: 28
• Total formula weight: 685989.61

Authors

Loewe, J.,Stock, D.,Jap, B.,Zwickl, P.,Baumeister, W.,Huber, R. (deposition date: 1994-12-19, release date: 1996-06-20, Last modification date: 2024-02-14)

Primary citation

Lowe, J.,Stock, D.,Jap, B.,Zwickl, P.,Baumeister, W.,Huber, R.
Crystal structure of the 20S proteasome from the archaeon T. acidophilum at 3.4 A resolution.
Science, 268:533-539, 1995

PubMed Abstract: The three-dimensional structure of the proteasome from the archaebacterium Thermoplasma acidophilum has been elucidated by x-ray crystallographic analysis by means of isomorphous replacement and cyclic averaging. The atomic model was built and refined to a crystallographic R factor of 22.1 percent. The 673-kilodalton protease complex consists of 14 copies of two different subunits, alpha and beta, forming a barrel-shaped structure of four stacked rings. The two inner rings consist of seven beta subunits each, and the two outer rings consist of seven alpha subunits each. A narrow channel controls access to the three inner compartments. The alpha 7 beta 7 beta 7 alpha 7 subunit assembly has 72-point group symmetry. The structures of the alpha and beta subunits are similar, consisting of a core of two antiparallel beta sheets that is flanked by alpha helices on both sides. The binding of a peptide aldehyde inhibitor marks the active site in the central cavity at the amino termini of the beta subunits and suggests a novel proteolytic mechanism.

PubMed: 7725097

Experimental method

X-RAY DIFFRACTION (3.4 Å)