E1 component of pyruvate dehydrogenase complex does not regulate the expression of NADPH-ferredoxin reductase in Azotobacter vinelandii.
In Azotobacter vinelandii, the E1 component of pyruvate dehydrogenase complex (PDHE1) is proposed to be a key regulatory protein in an oxidative stress management system that responds to superoxide. This proposal was tested by constructing an A. vinelandii mutant that had a disruption of aceE gene encoding PDHE1. This mutant exhibited wild-type exponential growth and a normal response to oxidative stress induced by paraquat. Electrophoretic mobility-shift assays revealed that a protein previously shown to bind to a paraquat-activatable DNA promoter was still present in the extract prepared from the mutant, implying that the protein cannot be PDHE1. These observations strongly contradict the previous claim that PDHE1 is a DNA-binding protein that is directly involved in the A. vinelandii oxidative stress-regulatory system.
Park
Buem-Seek
BS
Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi 39762, USA.
Kwon
Young-Man
YM
Pyla
Rajkumar
R
Boyle
John A
JA
Jung
Yean-Sung
YS
D016948:Azotobacter vinelandii / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D005287:Ferredoxin-NADP Reductase / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000494:pharmacology; D030481:Pyruvate Dehydrogenase (Lipoamide) / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; D005287:Ferredoxin-NADP Reductase; D030481:Pyruvate Dehydrogenase (Lipoamide); D010269:Paraquat