Cloned (Comment) | Organism |
---|---|
gene RCAP_rcc01743, recombiant overexpression in Escherichia coli | Rhodobacter capsulatus |
Protein Variants | Comment | Organism |
---|---|---|
additional information | generation of DsbA- mutants from strain MT1131, which form filamentous and osmosensitive cells at 35°C under Res growth conditions on enriched medium, where bioavailable Cu is limited. In contrast, these mutants grow normally at 25°C, but they produce very low levels of cbb3-Cox. Upon supplementation of the growth media with redox-active chemicals, they can grow normally and produce active cbb3-Cox. Overproduction of the Cu importer CcoA partially restores the cbb3-Cox defect, suggesting defective Cu incorporation into this enzyme in the absence of DsbA. Generation of DsbA- cbb3-Cox- and DsbA- bd-Qox- double mutants. Strain MD20 (1dsbA::kan) is used as a recipient, selecting for antibiotic resistance under growth permissive conditions. The double mutants thus obtained are tested for their temperature sensitive Res growth (ResTs) and Cu2+-suppressible phenotypes on MPYE at 35°C. Appropriate merodiploids are constructed by introducing the plasmids pDsbA, pSenC and pBK69 (CcoA) carrying wild-type alleles of dsbA, senC and ccoA, respectively into the DsbA- and DsbA- SenC-mutants using triparental crosses. Mutants lacking DsbA are able to grow via photosynthesis, albeit at a slower rate, on both enriched and minimal growth media, but can grow by aerobic respiration only on minimal, and not on enriched medium, at normal temperature (35°C). The DsbADELTA mutants revert readily on enriched medium at 35°C to regain Res growth ability. Proteomic analyses show that in the absence of DsbA the protease DegP is overproduced, and that the revertants contain mutations that lower DegP activity. DegP is usually less abundant and acts as a chaperone at lower temperatures. Phenotypes, overview | Rhodobacter capsulatus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
periplasm | - |
Rhodobacter capsulatus | - |
- |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 glutathione + protein-disulfide | Rhodobacter capsulatus | - |
glutathione-disulfide + protein-dithiol | - |
? | |
2 glutathione + protein-disulfide | Rhodobacter capsulatus NBRC 16581 | - |
glutathione-disulfide + protein-dithiol | - |
? | |
2 glutathione + protein-disulfide | Rhodobacter capsulatus ATCC BAA-309 | - |
glutathione-disulfide + protein-dithiol | - |
? | |
2 glutathione + protein-disulfide | Rhodobacter capsulatus SB1003 | - |
glutathione-disulfide + protein-dithiol | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Rhodobacter capsulatus | D5AU49 | - |
- |
Rhodobacter capsulatus ATCC BAA-309 | D5AU49 | - |
- |
Rhodobacter capsulatus NBRC 16581 | D5AU49 | - |
- |
Rhodobacter capsulatus SB1003 | D5AU49 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 glutathione + protein-disulfide | - |
Rhodobacter capsulatus | glutathione-disulfide + protein-dithiol | - |
? | |
2 glutathione + protein-disulfide | - |
Rhodobacter capsulatus NBRC 16581 | glutathione-disulfide + protein-dithiol | - |
? | |
2 glutathione + protein-disulfide | - |
Rhodobacter capsulatus ATCC BAA-309 | glutathione-disulfide + protein-dithiol | - |
? | |
2 glutathione + protein-disulfide | - |
Rhodobacter capsulatus SB1003 | glutathione-disulfide + protein-dithiol | - |
? |
Synonyms | Comment | Organism |
---|---|---|
DsbA | - |
Rhodobacter capsulatus |
RCAP_rcc01743 | - |
Rhodobacter capsulatus |
thiol-disulfide oxidoreductase | - |
Rhodobacter capsulatus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Rhodobacter capsulatus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.2 | - |
assay at | Rhodobacter capsulatus |
General Information | Comment | Organism |
---|---|---|
evolution | DsbA is a periplasmic thiol-disulfide oxidoreductase that belongs to the thioredoxin family of proteins with a CxxC conserved domain | Rhodobacter capsulatus |
malfunction | the purple non-sulfur bacterium Rhodobacter capsulatus mutants lacking DsbA show severe temperature-sensitive and medium-dependent respiratory growth defects. Absence of thiol-disulfide oxidoreductase DsbA impairs cbb3-type cytochrome c oxidase (cbb3-Cox) biogenesis in Rhodobacter capsulatus. Absence of DsbA, besides impairing the maturation of the c-type cytochrome subunits, also affects the incorporation of Cu into the catalytic subunit of cbb3-Cox. Defective high affinity Cu acquisition pathway, which includes the MFS-type Cu importer CcoA, and lower production of the c-type cytochrome subunits lead together to improper assembly and degradation of cbb3-Cox. DsbA- and several cbb3-Cox biogenesis mutants exhibit similar phenotypes. Mutational analysis of enzyme function, overview | Rhodobacter capsulatus |
physiological function | the thiol-disulfide oxidoreductase DsbA carries out oxidative folding of extra-cytoplasmic proteins by catalyzing the formation of intramolecular disulfide bonds. It has an important role in various cellular functions, including cell division. DsbA activity is required for full respiratory capability of Rhodobacter capsulatus, and in particular, for proper biogenesis of its cbb3-type cytochrome c oxidase (cbb3-Cox). Enzyme DsbA facilitates oxidative folding of extra-cytoplasmic proteins by catalyzing the formation of intramolecular disulfide bonds between two reactive Cys residues of its substrates, which include the c-type apocyts with their conserved CxxCH heme-binding sites. Reduced DsbA is re-oxidized by its recycling partner DsbB, which then transfers the reducing equivalents to the Q pool, and eventually to the electron transport chain | Rhodobacter capsulatus |