Open AccessTwo‐stage model for integration of the lysis protein E of ΦX174 into the cell envelope of Escherichia coli
Author(s) -
Schön Petra,
Schrot Gerald,
Wanner Gerhard,
Lubitz Werner,
Witte Angela
Publication year - 1995
Publication title -
fems microbiology reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.91
H-Index - 212
eISSN - 1574-6976
pISSN - 0168-6445
DOI - 10.1111/j.1574-6976.1995.tb00203.x
Subject(s) - cell envelope , lysis , cytoplasm , inner membrane , biology , fusion protein , escherichia coli , proteinase k , streptavidin , bacterial outer membrane , biophysics , biochemistry , microbiology and biotechnology , membrane , recombinant dna , biotin , enzyme , gene
As a tool for determining the topology of the small, 91‐amino acid ΦX174 lysis protein E within the envelope complex of Escherichia coli , a lysis active fusion of protein E with streptavidin (E‐FXa‐StrpA) was used. The E‐FXa‐StrpA fusion protein was visualised using immune electron microscopy with gold‐conjugated anti‐streptavidin antibodies within the envelope complex in different orientations. At the distinct areas of lysis characteristic for protein E, the C‐terminal end of the fusion protein was detected at the surface of the outer membrane, whereas at other areas the C‐terminal portion of the protein was located at the cytoplasmic side of the inner membrane. These results suggest that a conformational change of protein E is necessary to induce the lysis process, an assumption supported by proteinase K protection studies. The immune electron microscopic data and the proteinase K accessibility studies of the E‐FXa‐StrA fusion protein were used for the working model of the E‐mediated lysis divided into three phases: phase 1 is characterised by integration of protein E into the inner membrane without a cytoplasmic status in a conformation with its C‐terminal part facing the cytoplasmic side; phase 2 is characterised by a conformational change of the protein transferring the C‐terminus across the inner membrane; phase 3 is characterised by a fusion of the inner and outer membranes and is associated with a transfer of the C‐terminal domain of protein E towards the surface of the outer membrane of E. coli.