Abstract
Eukaryotic 2-Cys peroxiredoxins (2-Cys Prxs) not only act as antioxidants, but also appear to regulate hydrogen peroxide-mediated signal transduction. We show that bacterial 2-Cys Prxs are much less sensitive to oxidative inactivation than are eukaryotic 2-Cys Prxs. By identifying two sequence motifs unique to the sensitive 2-Cys Prxs and comparing the crystal structure of a bacterial 2-Cys Prx at 2.2 angstrom resolution with other Prx structures, we define the structural origins of sensitivity. We suggest this adaptation allows 2-Cys Prxs to act as floodgates, keeping resting levels of hydrogen peroxide low, while permitting higher levels during signal transduction.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Motifs
-
Amino Acid Sequence
-
Bacteria / enzymology
-
Binding Sites
-
Catalysis
-
Crystallography, X-Ray
-
Cysteine / metabolism
-
Disulfides / chemistry
-
Disulfides / metabolism
-
Evolution, Molecular
-
Humans
-
Hydrogen Peroxide / metabolism*
-
Models, Chemical
-
Models, Molecular
-
Molecular Sequence Data
-
Oxidation-Reduction
-
Peroxidases / chemistry*
-
Peroxidases / metabolism*
-
Peroxiredoxins
-
Protein Conformation
-
Protein Folding
-
Protein Structure, Secondary
-
Salmonella typhimurium / enzymology*
-
Sequence Alignment
-
Signal Transduction*
-
Sulfenic Acids / metabolism
-
Sulfinic Acids / metabolism
-
Yeasts / enzymology
Substances
-
Disulfides
-
Sulfenic Acids
-
Sulfinic Acids
-
Hydrogen Peroxide
-
Peroxidases
-
Peroxiredoxins
-
Cysteine