Increased synthesis of an Escherichia coli membrane protein suppresses F exclusion of bacteriophage T7.
Increased synthesis of the protein FxsA alleviates the exclusion of T7 in cells harboring the F plasmid. In contrast to wild-type or cells defective in fxsA, overexpression of fxsA+ allows T7 to form plaques at normal efficiency even though the burst size is reduced to about half that obtained on the isogenic F- strain. No defect in DNA synthesis was observed but late protein synthesis remains partially inhibited and a reduced level of cell leakiness, a prominent feature of F+ cells abortively infected by T7, persists. The FxsA protein is shown to be a cytoplasmic membrane protein. How T7 avoids exclusion by F in cells that exhibit increased levels of FxsA is discussed in terms of its membrane localization.
Wang
W F
WF
Department of Microbiology and Institute for Cell and Molecular Biology, University of Texas, Austin, TX 78712-1095, USA.
Margolin
W
W
Molineux
I J
IJ
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D017123:Bacteriophage T7 / Q000235:genetics*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics / Q000821:virology*; D029968:Escherichia coli Proteins; D005144:F Factor / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000096:biosynthesis*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009154:Mutation; D009711:Nucleotides / Q000032:analysis; D011993:Recombinant Fusion Proteins; D013489:Suppression, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D009711:Nucleotides; D011993:Recombinant Fusion Proteins; C121882:fxsA protein, E coli