Improved soluble expression of the gene encoding amylolytic enzyme Amo45 by fusion with the mobile-loop-region of co-chaperonin GroES inEscherichia coli.
The gene encoding the amylolytic enzyme Amo45, originating from a metagenomic project, was retrieved by a consensus primer-based approach for glycoside hydrolase (GH) family 57 enzymes. Family 57 contains mainly uncharacterized proteins similar to archaeal thermoactive amylopullulanases. For characterization of these family members soluble, active enzymes have to be produced in sufficient amounts. Heterologous expression ofamo45inE.coliresulted in low yields of protein, most of which was found in inclusion bodies. To improve protein production and to increase the amount of soluble protein, two different modifications of the gene were applied. The first was fusion to an N-terminal His-tag sequence which increased the yield of protein, but still resulted in high amounts of inclusion bodies. Co-expression with chaperones enhanced the amount of soluble protein 4-fold. An alternative modification was the attachment of a peptide consisting of the amino acid sequence of the mobile-loop of the co-chaperonin GroES ofE.coli. This sequence improved the soluble protein production 5-fold compared to His6-Amo45 and additional expression of chaperones was unnecessary.
Universität Stuttgart, Institut für Industrielle Genetik , Stuttgart , Germany.
Lei
L
Wang
Universität Stuttgart, Institut für Industrielle Genetik , Stuttgart , Germany.
Hildegard
H
Watzlawick
Matis Ltd. , Reykjavik , Iceland.
Olafur
O
Fridjonsson
Matis Ltd. , Reykjavik , Iceland ; Department of Biology, University of Iceland, Faculty of Life and Environmental Sciences , Reykjavik , Iceland.
Gudmundur
G
Hreggvidsson
Universität Stuttgart, Institut für Industrielle Genetik , Stuttgart , Germany.
Josef
J
Altenbuchner
Fusion with the mobile-loop of GroES; Metagenome mining; chaperones; expression in E.coli; glycoside hydrolase family 57