title: Construction of an artificial secYEG operon allowing high level secretion of α-amylase.
abstract: The key components of the major secretion pathway in bacteria, the Sec pathway, are the proteins SecA, an ATPase that generates the energy required for protein translocation, and the heterotrimeric protein complex SecYEG, which functions as the preprotein-conducting channel through the cytoplasmic membrane, named translocon. Overexpression of exoproteins can cause jamming of the membrane, e.g., due to a shortage of translocons. Therefore, we decided to increase the number of translocons by first creating an artificial secYEG operon and then fusing it to an inducible promoter. By Western- and Northern-blot analysis, we could first show that the amount of the SecY protein and the secYEG transcript can be increased after addition of the inducer. Next, we proved by immunoblot experiments that the amount of α-amylase secreted in the presence of increased amounts of SecYEG proteins is enhanced. Therefore, increasing the number of translocons is accompanied by a concomitant increase in the amount exoenzymes. This finding will be of importance for high-level secretion of recombinant proteins.
authors.affiliation: Institute of Genetics, University of Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: Kelly C L
authors.initials: KC
authors.lastname: Mulder
authors.forename: Joanna
authors.initials: J
authors.lastname: Bandola
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schumann
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics*; D009876:Operon / Q000235:genetics; D000069816:SEC Translocation Channels; D000516:alpha-Amylases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D000069816:SEC Translocation Channels; D000516:alpha-Amylases; D000251:Adenosine Triphosphatases