Inhibition of Escherichia coli B by homoarginine.
Homoarginine inhibits the growth of Escherichia coli B, but not of E. coli K-12. These two strains also differ in regard to repressibility of the arginine-forming enzymes. In K-12, arginine acts as a repressor whereas in B it does not. The latter difference is determined by different alleles of a regulator gene, arg R. In K-12 x B crosses, it was shown that the genetic determinant for homoarginine sensitivity is closely linked to or identical with arg R. Homoarginine-resistant mutants of B were isolated. The biochemical mechanism of homoarginine inhibition is not known. However, whether or not a strain is sensitive to homoarginine seems to depend on the intracellular level of arginine. In B this level is relatively low and inflexible as a result of the action of a repressor whose formation is determined by the B-specific allele of arg R.
D001120:Arginine / Q000378:metabolism*; D002874:Chromosome Mapping; D004794:Enzyme Repression; D004926:Escherichia coli / Q000378:metabolism; D005823:Genetics; D008967:Molecular Biology; D009952:Ornithine / Q000378:metabolism
D001120:Arginine; D009952:Ornithine