FdnH (PA4811) is the iron-sulfur (beta) subunit of the membrane-bound, nitrate-inducible respiratory formate dehydrogenase FdnGHI of Pseudomonas aeruginosa. It has four ferredoxin-type cysteine clusters that bind four [4Fe-4S] clusters and a single C-terminal transmembrane helix that anchors it to the cytoplasmic membrane. It carries electrons from the formate-oxidising molybdenum site of FdnG to the haem b groups of the membrane cytochrome FdnI, which reduces quinone. The enzyme is made during anaerobic growth on nitrate, when it and nitrate reductase form a short formate-to-nitrate respiratory chain.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Cytoplasmic membrane location from combined automated annotation. Reason: FdnH has a C-terminal transmembrane anchor, and the P. aeruginosa FDH was purified from a membrane particle fraction with nitrate reductase. Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt TRANSMEM 256..273 PMID:3038081 The separation of the FDH enzyme from nitrate reductase (NiR), which are found together in a particle fraction and constitute the short respiratory chain of this bacterium |
| GO:0009061 anaerobic respiration | IBA GO_REF:0000033 | ACCEPT | Summary: IBA anaerobic respiration from E. coli FdnH/FdoH/HybA seeds. Reason: FdnH is the electron-transfer subunit of the formate-to-nitrate respiratory chain made during anaerobic growth on nitrate. Supporting Evidence: PMID:3038081 The purification of formate dehydrogenase (FDH) from Pseudomonas aeruginosa after anaerobic growth on nitrate-containing medium was carried out. |
| GO:0009061 anaerobic respiration | IEA GO_REF:0000104 | ACCEPT | Summary: UniRule anaerobic respiration. Reason: Same claim as the IBA row. Supporting Evidence: PMID:3038081 The purification of formate dehydrogenase (FDH) from Pseudomonas aeruginosa after anaerobic growth on nitrate-containing medium was carried out. |
| GO:0009326 formate dehydrogenase complex | IBA GO_REF:0000033 | ACCEPT | Summary: IBA formate dehydrogenase complex. Reason: FdnH is the beta subunit of the FdnGHI complex; the purified P. aeruginosa FDH contained a [4Fe-4S] cluster together with the Mo and haem centres. Supporting Evidence: PMID:3038081 These techniques have allowed the haem, iron-sulphur clusters and molybdenum components to be detected |
| GO:0009326 formate dehydrogenase complex | IEA GO_REF:0000104 | ACCEPT | Summary: UniRule formate dehydrogenase complex. Reason: Same claim as the IBA row. Supporting Evidence: PMID:3038081 These techniques have allowed the haem, iron-sulphur clusters and molybdenum components to be detected |
| GO:0015944 formate oxidation | IBA GO_REF:0000033 | ACCEPT | Summary: IBA formate oxidation. Reason: FdnH carries the electrons released by formate oxidation out of the catalytic subunit; formate oxidation by the complex depends on this step. Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt The beta chain is an electron transfer unit containing 4 cysteine clusters involved in the formation of iron-sulfur centers. |
| GO:0015944 formate oxidation | IEA GO_REF:0000120 | ACCEPT | Summary: Combined automated formate oxidation. Reason: Same claim as the IBA row. Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt NCBIfam; TIGR01582; FDH-beta; 1. |
| GO:0016020 membrane | IEA GO_REF:0000002 | MODIFY | Summary: Generic membrane location. Reason: Correct but general; the specific location is the cytoplasmic (plasma) membrane, which the gene already carries (GO:0005886). Proposed replacements: plasma membrane Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt TRANSMEM 256..273 |
| GO:0036397 formate dehydrogenase (quinone) activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN001732897 (FdnH/FdoH clade, 3 seeds, 18 leaf IBAs). Seeds are E. coli FdnH (P0AAJ3, IDA PMID:1099093) and FdoH (P0AAJ5, IDA PMID:1504073) plus this gene (PseudoCAP IDA, PMID:3038081). Reason: The complex-level activity is annotated to the beta subunits on the same convention as in E. coli, and the IBD stands on the two E. coli seeds alone. Strictly FdnH contributes an electron-transfer step to the complex activity rather than catalysing it alone; that is captured in core_functions with contributes_to_molecular_function. Supporting Evidence: PMID:3038081 The separation of the FDH enzyme from nitrate reductase (NiR), which are found together in a particle fraction and constitute the short respiratory chain of this bacterium |
| GO:0036397 formate dehydrogenase (quinone) activity | IDA PMID:3038081 Purification and properties of formate dehydrogenase from Ps... | ACCEPT | Summary: PseudoCAP IDA, the PTN001732897 seed row. Activity of the purified FDH complex, which contained a [4Fe-4S]+ cluster attributable to FdnH. Reason: Seed verdict SOUND as a complex-level activity: a biochemical assay of purified FDH, not an operon mutant phenotype, annotated to each subunit as EcoCyc does for E. coli FdnGHI. The paper predates gene assignments and I read only the abstract; attribution rests on fdnGHI being the only FDH-N-type cluster in PAO1. Supporting Evidence: PMID:3038081 The e.p.r. and m.c.d. spectra of the reduced state of FDH reveal the presence of an iron-sulphur cluster of the [4Fe-4S]+ type. |
| GO:0036397 formate dehydrogenase (quinone) activity | IEA GO_REF:0000104 | ACCEPT | Summary: UniRule formate dehydrogenase (quinone) activity. Reason: Same claim as the IDA and IBA rows. Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt NCBIfam; TIGR01582; FDH-beta; 1. |
| GO:0045333 cellular respiration | IEA GO_REF:0000002 | TOO GENERAL | Summary: Cellular respiration from the FdnH signatures. Reason: True but uninformative; GO:0009061 anaerobic respiration, accepted in this review, is an is_a descendant of GO:0045333. |
| GO:0051539 4 iron, 4 sulfur cluster binding | IEA GO_REF:0000120 | ACCEPT | Summary: 4Fe-4S cluster binding. Reason: FdnH has four ferredoxin-type cysteine clusters (16 cysteine ligands) and binds four [4Fe-4S] clusters; a [4Fe-4S]+ signal was seen in the purified P. aeruginosa FDH. Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt Binds 4 [4Fe-4S] clusters per subunit. PMID:3038081 The e.p.r. and m.c.d. spectra of the reduced state of FDH reveal the presence of an iron-sulphur cluster of the [4Fe-4S]+ type. |
| GO:0009055 electron transfer activity | ISS file:PSEAE/fdnH/fdnH-uniprot.txt | NEW | Summary: Proposed subunit-level molecular function. FdnH relays electrons from FdnG to FdnI through its [4Fe-4S] clusters; E. coli FdnH (P0AAJ3) carries this term by IDA. Reason: The gene otherwise has only the complex-level activity and cofactor binding; electron transfer is what the subunit itself does. Supporting Evidence: file:PSEAE/fdnH/fdnH-uniprot.txt The beta chain is an electron transfer unit containing 4 cysteine clusters involved in the formation of iron-sulfur centers. |
Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)