Molecular cloning and co-expression of Thermoplasma volcanium proteasome subunit genes

Kocabıyık, Semra
Ozdemir, Inci
Zwickl, Peter
Ozdogan, Seda
In this study we describe, the construction of a co-expression vector allowing simultaneous production of Thermoplasma volcanium 20S proteasome alpha- and beta-subunits in Escherichia coli. This heterologous expression system provided high level production of fully active 205 proteasome that can be purified easily by using a conventional two-step chromatographic technique. The recombinant proteasome was purified to homogeneity 12-fold with a specific activity of 26.5 U/mg. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of two unique bands of alpha-(24 kDa) and beta-(21 kDa) subunits which were combined into proteolytically active proteasome complex in vivo when they were co-expressed in E. coli. The predominant peptide hydrolyzing activity was measured with typical chromogenic substrate (Ala-Ala-Phe-pNA) for chymotrypsin-like activity. The sequence analyses of the subunit genes showed that functional domains and residues including catalytic groups are highly conserved as compared to other archaeal proteasomes.

Citation Formats
S. Kocabıyık, I. Ozdemir, P. Zwickl, and S. Ozdogan, “Molecular cloning and co-expression of Thermoplasma volcanium proteasome subunit genes,” PROTEIN EXPRESSION AND PURIFICATION, vol. 73, pp. 223–230, 2010, Accessed: 00, 2020. [Online]. Available: