Proline Metabolism IncreaseskatGExpression and Oxidative Stress Resistance in Escherichia coli

• DOI: 10.1128/jb.02282-14
• Publication Date: 2014-11-11T05:10:25Z
• Authors: Lu Zhang; James R. Alfano; Donald F. Becker
• Keywords: Proline dehydrogenase; Regulon

The oxidation of l -proline to glutamate in Gram-negative bacteria is catalyzed by the proline utilization A (PutA) flavoenzyme, which contains dehydrogenase (PRODH) and Δ 1 -pyrroline-5-carboxylate (P5C) domains a single polypeptide. Previous studies have suggested that aside from providing energy, metabolism influences oxidative stress resistance different organisms. To explore this potential role mechanism, we characterized wild-type putA mutant strains Escherichia coli . Initial assays revealed strain was significantly more sensitive than parental strain. Expression PutA restored resistance, confirming depletion responsible for phenotype. Treatment cells with increased hydroperoxidase I (encoded katG ) expression activity. Furthermore, failed respond proline, indicating critical mechanism protection. global regulator OxyR activates along several other genes involved defense. In addition , grxA (glutaredoxin 1) trxC (thioredoxin 2) regulon, implicating Proline shown generate hydrogen peroxide, increases tolerance E. via preadaptive effect involving endogenous peroxide production enhanced catalase-peroxidase