DsbA
This article may be too technical for most readers to understand.(October 2015) |
DsbA | |||||||
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UniProt P0AEG4 | | ||||||
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DSBA oxidoreductase | |||||||||||
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Identifiers | |||||||||||
Symbol | DSBA | ||||||||||
Pfam | PF01323 | ||||||||||
InterPro | IPR001853 | ||||||||||
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DsbA is a bacterial thiol disulfide oxidoreductase (TDOR). DsbA is a key component of the Dsb (disulfide bond) family of enzymes. DsbA catalyzes intrachain disulfide bond formation as peptides emerge into the cell's periplasm.[2]
Structurally, DsbA contains a
disulfide bonds into nascent proteins. In equivalent terms, it catalyzes the oxidation of a pair of cysteine residues on the substrate protein. Most of the substrates for DsbA are eventually secreted, and include important toxins, virulence factors, adhesion machinery, and motility structures[4] DsbA is localized in the periplasm, and is more common in Gram-negative bacteria than in Gram-positive bacteria. Within the thioredoxin family, DsbA is the most strongly oxidizing member. Using glutathione oxidation as a metric, DsbA is ten times more oxidizing than protein disulfide-isomerase (the eukaryotic equivalent of DsbA). The extremely oxidizing nature of DsbA is due to an increase in stability upon reduction of DsbA, thereby imparting a decrease in energy of the enzyme when it oxidizes substrate.[5]
This feature is incredibly rare among proteins, as nearly all proteins are stabilized by the formation of disulfide bonds. DsbA's highly oxidizing nature is a result of hydrogen bond, electrostatic and helix-dipole interactions that favour the thiolate over the disulfide at the active site.
After donating its disulfide bond, DsbA is regenerated by the membrane-bound protein DsbB.
See also
- Disulfide bond formation protein B
- Disulfide bond formation protein C