Redox regulation of 3'-phosphoadenylylsulfate reductase from Escherichia coli by glutathione and glutaredoxins.
Inorganic sulfate (SO42-, S+VI) is reduced in vivo to sulfite (SO32-, S+IV) via phosphoadenylylsulfate (PAPS) reductase. Escherichia coli lacking glutathione reductase and glutaredoxins (gor-grxA-grxB-grxC-) barely grows on sulfate. We found that incubation of PAPS reductase with oxidized glutathione leads to enzyme inactivation with simultaneous formation of a mixed disulfide between glutathione and the active site Cys-239. A newly developed method based on thiol-specific fluorescent alkylation and gel electrophoresis showed that glutathionylated PAPS reductase is reduced by glutaredoxins via a monothiol mechanism. This glutathionylated species was also observed in poorly growing gor-grxA-grxB-grxC- cells expressing inactive glutaredoxin 2 (Grx2) C9S/C12S. However, it was absent in better growing cells expressing monothiol Grx2 C12S or wild type Grx2. Reversible glutathionylation may thus regulate the activity of PAPS reductase in vivo.
Lillig
Christopher Horst
CH
Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Scheeles Väg 2, 17177 Stockholm, Sweden.
Potamitou
Aristi
A
Schwenn
Jens-Dirk
JD
Vlamis-Gardikas
Alexios
A
Holmgren
Arne
A
D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D017353:Gene Deletion; D054477:Glutaredoxins; D005978:Glutathione / Q000494:pharmacology; D019803:Glutathione Disulfide / Q000494:pharmacology; D007700:Kinetics; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry; D011506:Proteins / Q000235:genetics*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin
D054477:Glutaredoxins; D010446:Peptide Fragments; D011506:Proteins; D010088:Oxidoreductases; C052449:3'-phosphoadenylyl-5'-phosphosulfate reductase; D014357:Trypsin; D005978:Glutathione; D019803:Glutathione Disulfide