title: Studies on lipase directed export of Escherichia coli beta-lactamase in Staphylococcus carnosus.
abstract: The lipase (lip) gene of Staphylococcus hyicus was used to study the expression of the Escherichia coli beta-lactamase (bla) gene in S. carnosus. The bla gene, devoid of its promotor and most of the signal sequence, was fused to the lip structural gene at various positions. A set of 11 secretion vectors (pLL beta 1 to pLL beta 11) was isolated and analysed. All secretion vectors caused beta-lactamase production and activity in S. carnosus. However, the amount of hybrid proteins secreted was influenced by the length of the NH2-terminal lipase portion. An increased concentration, comparable to that of the native lipase, of secreted lipase/beta-lactamase hybrid proteins was only found when the lipase portion of the construct comprised more than 101 amino acids of the NH2-terminal region of the lipase preprotein; the proposed lipase signal peptide is 36 amino acids long. If the hybrid proteins constructed contained 101 or less amino acids of the NH2-terminal lipase preprotein, only low amounts of secreted hybrid proteins were detectable and a significant portion of the hybrid proteins and beta-lactamase activity was found in the cellular fraction. The results indicate that the lipase possesses adjacent to the signal peptide a peptide domain that is essential for the secretion of the lipase/beta-lactamase hybrid proteins.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D005822:Genetic Vectors; D008049:Lipase / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D013210:Staphylococcus / Q000201:enzymology / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D008049:Lipase; D004262:DNA Restriction Enzymes; D001618:beta-Lactamases