Critical elements in proteasome assembly.

P Zwickl; J Kleinz; W Baumeister

doi:10.1038/nsb1194-765

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PubMed · 7634086

Critical elements in proteasome assembly.

P Zwickl·J Kleinz·W Baumeister

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Abstract

Coexpression of both subunits of the Thermoplasma proteasome in Escherichia coli yields fully assembled and proteolytically active proteasomes. Post-translational processing of the beta-subunit occurs in E. coli as it does in Thermoplasma. Coexpression of the alpha-subunit and the beta delta pro-subunit, a mutant beta-subunit lacking the propeptide, also yields fully assembled and active proteasomes. This indicates that the beta-propeptide is not essential for the folding and assembly of Thermoplasma proteasomes. Separately expressed alpha-subunits assemble into heptameric rings indistinguishable from the terminal rings of a proteasome. Mutational analysis shows that the amino terminus, which is highly conserved in all proteasomal alpha-type proteins, is essential for assembly. In the absence of alpha-subunits the beta-subunits are monomeric and post-translational processing of the beta-propeptide does not occur.

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Amino Acid Sequence Cloning, Molecular Cysteine Endopeptidases Enzyme Precursors Escherichia coli Molecular Sequence Data Multienzyme Complexes Mutation Proteasome Endopeptidase Complex Protein Conformation Protein Folding Protein Processing, Post-Translational Sequence Homology, Amino Acid Thermoplasma Journal Article

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P Zwickl, J Kleinz, W Baumeister. 1994. Critical elements in proteasome assembly.. https://doi.org/10.1038/nsb1194-765

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