The appearance of cytoplasmic membranes of Escherichia coli cells in freeze-fracture electron microscopy after stringent and relaxed response.
Guanosine-5'-diphosphate-3'-diphosphate (ppGpp), an effector for many metabolic pathways, is synthesized by the relA gene product after amino acid limitation. Studies of stringent controlled Escherichia coli CP78 (relA+) and relaxed controlled E. coli CP79 (relA-) were carried out to test whether these strains differ in the appearance of their cytoplasmic membranes after induction of stringent and relaxed response. Cytoplasmic membrane structures of the cells were investigated by freeze-fracture electron microscopy after cooling the cells. The obtained micrographs showed a net-like distribution of the particles in the cytoplasmic membranes of relaxed controlled cells whereas such a pattern was not detectable in the stringent controlled counterparts.
Gitter
B
B
Hans-Knöll-Institut für Naturstoff-Forschung e.V., Jena, Germany.
Richter
W
W
Riesenberg
D
D
Meyer
H W
HW
D000596:Amino Acids / Q000172:deficiency; D002462:Cell Membrane / Q000648:ultrastructure; D004926:Escherichia coli / Q000378:metabolism / Q000648:ultrastructure*; D005614:Freeze Fracturing; D006159:Guanosine Tetraphosphate / Q000096:biosynthesis; D008854:Microscopy, Electron; D013045:Species Specificity
D000596:Amino Acids; D006159:Guanosine Tetraphosphate