Identification of hydrophobic proteins FepD and FepG of the Escherichia coli ferrienterobactin permease.
In Escherichia coli, iron assimilation by means of the siderophore enterobactin requires two hydrophobic cytoplasmic membrane proteins, FepD and FepG, which are essential components of a binding-protein-dependent transport system. Such components are typically difficult to detect. Here we report observation of the fepD and fepG gene products in polyacrylamide gels; they appeared as diffuse bands at positions consistent with smaller sizes than those predicted by sequence analysis. Translational coupling was suggested by the lack of a detectable product from the fepG message in the absence of translation of the upstream fepD message. The orientation of FepD/FepG in the membrane was predicted based on their similarities in sequence and hydrophobicity to FhuB.
Chenault
S S
SS
Department of Microbiology, University of Texas, Austin 78712-1095.
Earhart
C F
CF
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000302:isolation & purification*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface
D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D011956:Receptors, Cell Surface; C029489:enterobactin receptor; D007501:Iron