Proline Metabolism IncreaseskatGExpression and Oxidative Stress Resistance in Escherichia coli
2. Zero hunger
0301 basic medicine
570
0303 health sciences
Proline
Escherichia coli Proteins
Biophysics
Life Sciences
Gene Expression
Membrane Proteins
Catalase
Biochemistry
3. Good health
Oxidative Stress
03 medical and health sciences
Other Biochemistry
Bacterial Proteins
Stress, Physiological
and Structural Biology
Escherichia coli
Gene Deletion
Biotechnology
DOI:
10.1128/jb.02282-14
Publication Date:
2014-11-11T05:10:25Z
AUTHORS (3)
ABSTRACT
The oxidation ofl-proline to glutamate in Gram-negative bacteria is catalyzed by the proline utilization A (PutA) flavoenzyme, which contains proline dehydrogenase (PRODH) and Δ1-pyrroline-5-carboxylate (P5C) dehydrogenase domains in a single polypeptide. Previous studies have suggested that aside from providing energy, proline metabolism influences oxidative stress resistance in different organisms. To explore this potential role and the mechanism, we characterized the oxidative stress resistance of wild-type andputAmutant strains ofEscherichia coli. Initial stress assays revealed that theputAmutant strain was significantly more sensitive to oxidative stress than the parental wild-type strain. Expression of PutA in theputAmutant strain restored oxidative stress resistance, confirming that depletion of PutA was responsible for the oxidative stress phenotype. Treatment of wild-type cells with proline significantly increased hydroperoxidase I (encoded bykatG) expression and activity. Furthermore, the ΔkatGstrain failed to respond to proline, indicating a critical role for hydroperoxidase I in the mechanism of proline protection. The global regulator OxyR activates the expression ofkatGalong with several other genes involved in oxidative stress defense. In addition tokatG, proline increased the expression ofgrxA(glutaredoxin 1) andtrxC(thioredoxin 2) of the OxyR regulon, implicating OxyR in proline protection. Proline oxidative metabolism was shown to generate hydrogen peroxide, indicating that proline increases oxidative stress tolerance inE. colivia a preadaptive effect involving endogenous hydrogen peroxide production and enhanced catalase-peroxidase activity.
SUPPLEMENTAL MATERIAL
Coming soon ....
REFERENCES (66)
CITATIONS (81)
EXTERNAL LINKS
PlumX Metrics
RECOMMENDATIONS
FAIR ASSESSMENT
Coming soon ....
JUPYTER LAB
Coming soon ....