Export of FepA::PhoA fusion proteins to the outer membrane of Escherichia coli K-12.
A library of fepA::phoA gene fusions was generated in order to study the structure and secretion of the Escherichia coli K-12 ferric enterobactin receptor, FepA. All of the fusion proteins contained various lengths of the amino-terminal portion of FepA fused in frame to the catalytic portion of bacterial alkaline phosphatase. Localization of FepA::PhoA fusion proteins in the cell envelope was dependent on the number of residues of mature FepA present at the amino terminus. Hybrids containing up to one-third of the amino-terminal portion of FepA fractionated with their periplasm, while those containing longer sequences of mature FepA were exported to the outer membrane. Outer membrane-localized fusion proteins expressed FepA sequences on the external face of the outer membrane and alkaline phosphatase moieties in the periplasmic space. From sequence determinations of the fepA::phoA fusion joints, residues within FepA which may be exposed on the periplasmic side of the outer membrane were identified.
Murphy
C K
CK
Department of Microbiology, Medical College of Wisconsin, Milwaukee 53226.
Klebba
P E
PE
D000469:Alkaline Phosphatase / Q000235:genetics* / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D014357:Trypsin
D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C029489:enterobactin receptor; D000469:Alkaline Phosphatase; D014357:Trypsin