Regulation of Proline Degradation in Salmonella typhimurium
AUTOR(ES)
Dendinger, Susan
RESUMO
The pathway for proline degradation in Salmonella typhimurium appears to be identical to that found in Escherichia coli and Bacillus subtilis. Δ1-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 proline-degrading enzymes, proline oxidase and P5C dehydrogenase, are induced by proline and are subject to catabolite repression. Three types of mutants were isolated in which both enzymes are affected: constitutive mutants, mutants with reduced levels of enzyme activity, and mutants unable to produce either enzyme. Most of the mutants isolated for their lack of P5C dehydrogenase activity have a reduced level of proline oxidase activity. All the mutations are cotransducible. A genetic map of some of the mutations is presented. The actual effector of the pathway appears to be proline.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=248050Documentos Relacionados
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