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Role of the lipB gene product in the folding of the secreted lipase of Pseudomonas glumae
Author(s) -
Frenken Leon G. J.,
Groot Arjan,
Tommassen Jan,
Verrips C. Theo
Publication year - 1993
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1993.tb01719.x
Subject(s) - lipase , biology , periplasmic space , foldase , bacterial outer membrane , escherichia coli , bacillus subtilis , biochemistry , heterologous expression , gene product , microbiology and biotechnology , enzyme , gene , recombinant dna , bacteria , gene expression , genetics , groel
Summary The LipB protein of Pseudomonas glumae is essential for the production of active extracellular lipase encoded by the lipA gene. When lipase is overproduced in P. glumae in the absence of a functional lipB gene, the enzyme accumulates intracellularly in an inactive conformation. Heterologous expression of the lipase in Pseudomonas aeruginosa, Bacillus subtilis and Escherichia coli indicated that LipB is not directly involved in the trans location of the lipase across the inner or outer membrane. However, the presence of LipB was essential for obtaining active lipase and had a profound influence on the stability of the protein to proteolytic degradation. Inactive iipase, produced in the absence of LipB could be activated in vitro by unfolding and refolding, which demonstrates that LipB activity is not responsible for an essential covalent modification of the enzyme. We propose that LipB is a lipase‐specific foldase. Furthermore, proper folding of the lipase in the periplasm appears to be essential for Xcp‐mediated translocation across the outer membrane.