title: Molecular cloning of the Salmonella typhimurium lep gene in Escherichia coli.
abstract: A system is described which enabled the selection of a heterologous lep gene, encoding signal peptidase I, in Escherichia coli. It is based on complementation of an E. coli mutant, in which the synthesis of signal peptidase I can be regulated. With this system the lep gene of Salmonella typhimurium was cloned and the nucleotide sequence was determined. The S. typhimurium lep gene encodes a protein of 324 amino acids. Expression of the gene in the E. coli mutant resulted in suppression of growth inhibition and in the restoration of processing activity under conditions where synthesis of E. coli signal peptidase I was repressed. The cloned S. typhimurium signal peptidase I had an apparent molecular weight of 36,000 daltons, which is in agreement with the calculated molecular weight of 35,782 daltons. The system described for selection of the S. typhimurium lep gene may permit the cloning and expression of other heterologous signal peptidase I genes.
authors: Department of Genetics, Center of Biological Sciences, Haren, The Netherlands.
authors: J M
authors: JM
authors: van Dijl
authors: R
authors: R
authors: van den Bergh
authors: T
authors: T
authors: Reversma
authors: H
authors: H
authors: Smith
authors: S
authors: S
authors: Bron
authors: G
authors: G
authors: Venema
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics*; D012697:Serine Endopeptidases; D014158:Transcription, Genetic
chemical_list: D008565:Membrane Proteins; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase