Role of a C-Terminal Domain in the Structure and Surface Anchoring of the Tetragonal S-Layer of Aeromonas hydrophila
A number of species of Aeromonas are capable of producing S-layers which exhibit p4 symmetry (Stewart et al., 1986; Murray et al., 1988; Al-Karadaghi et al., 1988; Dooley et al., 1989; Kokka et al., 1990; Kokka et al., 1992). In wild type strains, these tetragonal S-layers are anchored to the surface of the Aeromonas cell and little, if any, assembled layer is released from the cell surface. However, A. salmonicida mutants which produce a lipopolysaccharide (LPS) deficient in 0-antigen chains (rough LPS), while still capable of assembling the S-layer protein subunits into an array, are unable to anchor this assembled array to their cell surface (Chart et al., 1984; Dooley et al., 1989). Indeed the released S-layer forms a stable sheet consisting of two exactly superimposed layers interacting through their inner surfaces (Dooley et al., 1989). In the case of A. hydrophila, an intact core LPS appears to be required to anchor the array to the cell surface because while rough strains can maintain S-layer on their surface, deep rough LPS mutants shed their S-layer (Dooley et al., 1988). The regions of the S-layer proteins participating in this anchoring of S-layer to the surface of the Aeromonas cells have not been identified.
KeywordsAEROMONAS HYDROPHILA Morphological Unit Surface Anchor Outer Membrane Fraction Tetragonal Surface
Unable to display preview. Download preview PDF.