Salmonella typhimurium proline mutants

Salmonella typhimurium proline mutants.

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...

Regulation of proline degradation in Salmonella typhimurium.

The pathway for proline degradation in Salmonella typhimurium appears to be identical to that found in Escherichia coli and Bacillus subtilis. Delta(1)-Pyrroline-5-carboxylic acid (P5C) is an intermediate in the pathway; its formation consumes molecular oxygen. Assays were devised for proline oxidase and the nicotinamide adenine dinucleotide phosphate-specific P5C dehydrogenase activities. Both...

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...