Open AccessMode of transfer of the phosphate‐binding protein through the cytoplasmic membrane in Escherichia coli
Author(s) -
Anba Jamila,
Pages JeanMarie,
Lazdunski Claude
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01407.x
Subject(s) - phos , periplasmic space , trypsin , cytoplasm , biochemistry , escherichia coli , membrane , phosphate , membrane protein , chemistry , biology , enzyme , gene
It has previously been demonstrated that the precursor form of the phosphate‐binding protein (pre‐PhoS) is accumulated in both the cytoplasmic membrane and the cytoplasm under conditions of phosphate‐binding protein (PhoS) hyperproduction in Escherichia coli [11]. In this study, the trypsin accessibility of these 2 pre‐PhoS pools has been investigated in spheroplasts. The results demonstrate that the membrane‐associated pre‐PhoS is not accessible to trypsin, and thus has not been translocated. The sensitivity to trypsin of mature PhoS, membrane‐associated pre‐PhoS and cytoplasmic pre‐PhoS was compared. The results suggest a difference in conformation between membrane‐associated and cytoplasmic pre‐PhoS since the former is more trypsin‐sensitive than the latter. Mature PhoS is resistant to trypsin. The significance of these results with regard to the export mechanism for periplasmic proteins is discussed.