title: Extracellular accumulation of recombinant proteins fused to the carrier protein YebF in Escherichia coli.
abstract: Bacterial protein secretion is important in the life cycles of most bacteria, in which it contributes to the formation of pili and flagella and makes available extracellular enzymes to digest polymers for nutritional purposes and toxins to kill host cells in infections of humans, animals and plants. It is generally accepted that nonpathogenic laboratory strains of Escherichia coli, particularly K12 strains, do not secrete proteins into the extracellular medium under routine growth conditions. In this study, we report that commonly used laboratory strains secrete YebF, a small (10.8 kDa in the native form), soluble endogenous protein into the medium, challenging the status quo view that laboratory strains do not secrete proteins to the medium. We further show that 'passenger' proteins linked to the carboxyl end of YebF are efficiently secreted. The function of YebF is unknown, but its use as a carrier for transgenic proteins provides a tool to circumvent toxicity and other contamination issues associated with protein production in E. coli.
authors.affiliation: Membrane Protein Research Group, Department of Biochemistry, 474 Medical Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.
authors.forename: Guijin
authors.initials: G
authors.lastname: Zhang
authors.forename: Stephen
authors.initials: S
authors.lastname: Brokx
authors.forename: Joel H
authors.initials: JH
authors.lastname: Weiner
mesh_terms: D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D045604:Extracellular Fluid / Q000378:metabolism*; D008969:Molecular Sequence Data; D015202:Protein Engineering / Q000379:methods; D011993:Recombinant Fusion Proteins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D011993:Recombinant Fusion Proteins; C508772:YebF protein, E coli