EC Number   |
General Information |
Reference |
|---|
  1.8.4.15 | evolution |
while CtDsbA shares common structural and biochemical features with the DsbA-II group of DsbA proteins, especially, CtDsbA shares just 15% sequence identity with the canonical EcDsbA protein and approximately 20% sequence identity with other members of the structurally characterised DsbA-II class proteins that contain a second disulfide. The second disulfide of CtDsbA does not influence interaction with CtDsbB |
-, 758183 |
| 1.8.4.15 | malfunction |
deletion of the ncgl2478 gene increases the size of growth inhibition zones. Site-directed mutagenesis confirms Cys24 as the resolving Cys residue, while Cys21 is the nucleophilic cysteine that is oxidized to a sulfenic acid and then forms an intramolecular disulfide bond with Cys24 or a mixed disulfide with MSH under oxidative stress |
763778 |
| 1.8.4.15 | metabolism |
the enzyme acts as a direct donor of disulfides to newly synthesized periplasmic proteins |
757125 |
| 1.8.4.15 | metabolism |
the enzyme is required for production of disulfide-bonded proteins |
-, 757144 |
| 1.8.4.15 | metabolism |
the enzyme is required for protein disulfide bond formation in vivo. Disulfide-bonded enzyme is a potent oxidant and ideally suited for generating protein disulfide bonds |
756028 |
| 1.8.4.15 | metabolism |
the enzyme is responsible for catalyzing the formation of disulfide bonds in secreted and membrane-associated proteins |
755811 |
| 1.8.4.15 | metabolism |
the enzyme receives electrons preferentially from the mycothiol (MSH)/mycothione reductase (Mtr)/NADPH pathway, see EC 5.3.4.1 and EC 1.8.1.15 |
763778 |
| 1.8.4.15 | more |
the classic DsbA structure consists of a thioredoxin domain and an inserted alpha-helical bundle domain. The enzyme's active site is a Cys-Xaa-Xaa-Cys motif located at the N-terminus of helix H1. The sequence of the Xaa-Xaa dipeptide modulates the redox character of the enzyme. The catalytic surface of the protein features 3 loops: loop 1, (linking helix H1 and beta-strand B3), loop 2 (linking helix H6 and beta-strand B4) which contains a highly conserved cis-Pro residue, and loop 3 (linking helix H7 and beta-strand B5.) Together these loops govern the enzyme's redox properties and its interactions with protein substrates. CtDsbA has a second, non-catalytic disulfide, in addition to the enzymatically critical active site disulfide, this non-catalytic disulfide staples H3 and H5 of the inserted alpha-helix domain. In mutant CtDsbB-CCSS periplasmic loop 2 Cys98 and Cys104 are mutated to serines, in the presence of CtDsbB-CCSS or CtDsbB-SSCC, CtDsbA catalysed oxidation of the peptide substrate is markedly reduced relative to wild-type CtDsbB, although oxidation proceeds more rapidly than observed for negative controls containing only buffer, or the wild-type CtDsbB variant alone. The disulfide bonds present in periplasmic loops P1 and P2 of CtDsbB are each required for complete oxidation of CtDsbA. The second disulfide of CtDsbA does not influence interaction with CtDsbB |
-, 758183 |
| 1.8.4.15 | more |
the enzyme preserves a Cys-Pro-Phe-Cys active-site motif, which is presumed to be an exclusive characteristic of the DsbA-mycoredoxin 1 (Mrx1, EC 1.20.4.3) cluster. Cys24 is the resolving Cys residue, while Cys21 is the nucleophilic cysteine that is oxidized to a sulfenic acid and then forms an intramolecular disulfide bond with Cys24 or a mixed disulfide with MSH under oxidative stress |
763778 |
| 1.8.4.15 | physiological function |
disulfide bond protein A (DsbA) is the primary oxidase in the disulfide oxidative pathway of bacteria. DsbA catalyses the introduction of disulfide bonds into reduced and folding proteins in concert with a membrane protein partner DsbB. DsbB uses a quinone cofactor as an electron acceptor, and together the DsbA-DsbB pair ultimately shuttle electrons from a reduced protein substrate to molecular oxygen via the respiratory pathway. CtDsbA is directly oxidised by CtDsbB, in a reaction in which both periplasmic cysteine pairs of CtDsbB are required for complete activity. Potential role of CtDsbA in chlamydial envelope disulfide bonding, and importance of disulfide crosslinking of the Chlamydia envelope in infection and Chlamydia development |
-, 758183 |
