Characterization of factor IIIGLc in catabolite repression-resistant (crr) mutants of Salmonella typhimurium

Mutants of Salmonella typhimurium that are insensitive to catabolite repression of proline degradation.

In Salmonella typhimurium the two enzymes of proline catabolism, proline oxidase and Delta(1)-pyrroline-5-carboxylic acid dehydrogenase, are subject to catabolite repression when the cells are grown in the presence of glucose. Mutants partially relieved of catabolite repression (PutR) for the proline catabolic enzymes have been isolated by selection on agar plates containing glucose and proline...

6-Aminonicotinamide-resistant mutants of Salmonella typhimurium.

Resistance to the nicotinamide analog 6-aminonicotinamide has been used to identify the following three new classes of mutants in pyridine nucleotide metabolism. (i) pncX mutants have Tn10 insertion mutations near the pncA locus which reduce but do not eliminate the pncA product, nicotinamide deamidase. (ii) nadB (6-aminonicotinamide-resistant) mutants have dominant alleles of the nadB gene, wh...

Evidence for an altered operator specificity: catabolite repression control of the leucine operon in Salmonella typhimurium.

A mutation, GD-1, in the leucine operon imposed unusual growth characteristics upon a leucine auxotrophic strain bearing the leucine operator mutation, leu-500. The strain with the GD-1 mutation was able to grow on a minimal salts medium when citrate was the sole carbon source, but required leucine when glucose was present. Tests with a large number of carbohydrates suggest that in the strain b...

Proline Mutants of Salmonella Typhimurium.

CCORDING to previous analyses of 16 proline-requiring mutants of SalmonA d l a typhimurium, made genetically by NIELSEN (DEMEREC et al. 1954) and biochemically by JSANAZIR (1956; DEMEREC et al. 1955), the mutants fell into at least three groups. Recently, the number of proline-requiring mutants in our collection was increased to more than 200, and useful new techniques were devised or adapted f...

Salmonella typhimurium proline mutants.