A periplasmic reducing system protects single cysteine residues from oxidation.
The thiol group of the amino acid cysteine can be modified to regulate protein activity. The Escherichia coli periplasm is an oxidizing environment in which most cysteine residues are involved in disulfide bonds. However, many periplasmic proteins contain single cysteine residues, which are vulnerable to oxidation to sulfenic acids and then irreversibly modified to sulfinic and sulfonic acids. We discovered that DsbG and DsbC, two thioredoxin-related proteins, control the global sulfenic acid content of the periplasm and protect single cysteine residues from oxidation. DsbG interacts with the YbiS protein and, along with DsbC, regulates oxidation of its catalytic cysteine residue. Thus, a potentially widespread mechanism controls sulfenic acid modification in the cellular environment.
Depuydt
Matthieu
M
de Duve Institute, Université catholique de Louvain, B-1200 Brussels, Belgium.
Leonard
Stephen E
SE
Vertommen
Didier
D
Denoncin
Katleen
K
Morsomme
Pierre
P
Wahni
Khadija
K
Messens
Joris
J
Carroll
Kate S
KS
Collet
Jean-François
JF
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism*; D004220:Disulfides / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019897:Periplasm / Q000378:metabolism*; D033903:Periplasmic Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D013379:Substrate Specificity; D013434:Sulfenic Acids / Q000378:metabolism
D004220:Disulfides; D029968:Escherichia coli Proteins; D033903:Periplasmic Proteins; D013434:Sulfenic Acids; C545765:YbiS protein, E coli; D010088:Oxidoreductases; C109831:DsbG protein, E coli; D019704:Protein Disulfide-Isomerases; C526649:dsbC protein, E coli; D003545:Cysteine