INFLUENCE OF RELA LOCUS ON ELECTROPHORETIC MOBILITY OF A STRINGENT RELAXED ESCHERICHIA-COLI K-12 STRAIN PAIR

Stringent (relA(+)) and relaxed rel A(-)) controlled Escherichia coli cells differ in their regulation of many biochemical pathways such as phospholipid and lipopolysaccharide metabolism (LPS) after amino acid limitation. Because such differences could result in various cell enve lopes, cells of stringent controlled E. coli strain CP78 (relA(+)) and relaxed controlled E. coli strain CP79 (relA) were studied regarding their electrophoretic mobility. The graphs of the mobility distributio ns of both strains were different: cells of strain CP79 caused seconda ry peaks in addition to the main peaks whereas the mobility distributi ons of cells of strain CP78 showed only one maximum. In the pH range f rom 6.0 to 8.0 the location of the main peaks of cells of strain CP79 were changed to less negative values after induction of relaxed respon se. In contrast to this the stringent response in strain CP78 caused n o change of the mobility distributions.