The purification of M13 procoat, a membrane protein precursor.
Many membrane proteins and most secreted proteins are initially made as precursors with an N-terminal leader sequence. We now report the isolation of M13 procoat, the precursor of the membrane-bound form of M13 coat protein. There are 40 000 copies of M13 procoat protein/cell during M13 amber 7 virus infection. Purified procoat is quantitatively cleaved by isolated leader peptidase to yield mature-length coat protein. Rabbit antibodies to M13 procoat will precipitate procoat but not coat, suggesting that the antibody molecules are specifically recognizing the leader sequence or the conformation which it induces in the whole procoat molecule.
D000936:Antigen-Antibody Complex; D002213:Capsid / Q000302:isolation & purification* / Q000378:metabolism; D036022:Capsid Proteins; D002850:Chromatography, Gel / Q000379:methods; D003090:Coliphages / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism; D004926:Escherichia coli / Q000032:analysis; D007106:Immune Sera; D008565:Membrane Proteins; D011498:Protein Precursors / Q000302:isolation & purification* / Q000378:metabolism; D012697:Serine Endopeptidases
D000936:Antigen-Antibody Complex; D036022:Capsid Proteins; D007106:Immune Sera; D008565:Membrane Proteins; D011498:Protein Precursors; C025668:coat protein, Bacteriophage M13; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase