The filamentous bacteriophage assembly proteins require the bacterial SecA protein for correct localization to the membrane.
The noncapsid assembly proteins pI and pI of the filamentous bacteriophage f1 are inserted into the inner membrane of Escherichia coli via an internal signal sequence. Inhibition of the activity of SecA with low concentrations of sodium azide results in rapid accumulation of pI and pI proteins in the cytoplasm. However, both proteins are inserted into the membrane under the same conditions when synthesized in bacteria containing a secA azide resistance mutation. The other noncapsid assembly protein, pIV, is an outer membrane protein synthesized with a cleavable signal sequence. Wild-type bacteria accumulate the precursor to pIV when protein synthesis is in the presence of low concentrations of sodium azide. These results suggest that the f1 bacteriophage assembly proteins require SecA and consequently the bacterial Sec system to reach their proper membrane location.
Rapoza
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MP
Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710.
Webster
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D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001386:Azides / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D001435:Bacteriophages / Q000378:metabolism*; D001692:Biological Transport; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D019810:Sodium Azide; D014764:Viral Proteins / Q000378:metabolism*
D001386:Azides; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D014764:Viral Proteins; D019810:Sodium Azide; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins