Bfd (PA3530) is a small (73-residue) bacterioferritin-associated ferredoxin of Pseudomonas aeruginosa that carries a [2Fe-2S] cluster bound by a Fer2_BFD (BFD-like) domain and is induced by iron starvation. Bfd binds the BfrB subunits of the bacterioferritin complex and is required to mobilize stored iron from its core; the [2Fe-2S] cluster is needed for this, and electrons are thought to pass from the ferredoxin reductase FPR through Bfd and the BfrB heme to reduce the Fe(3+) mineral and release Fe(2+). Bfd is not an efficient electron donor to heme oxygenase.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0051537 2 iron, 2 sulfur cluster binding | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002205442 (Bfd family, 12 leaves in 12 taxa), seeded by E. coli Bfd (P0AE56) and Bfd itself. Reason: Expected self-seed reflecting Bfd's own IDA. E. coli Bfd has independent experimental [2Fe-2S] evidence (EcoCyc IDA PMID:8639572, PMID:8954950), so the IBD stands without this seed, and the cluster-binding cysteine domain is conserved across the clade. Supporting Evidence: PMID:17915950 Biochemical and spectroscopic investigations demonstrated that the bfd gene encodes a 73-amino acid protein (pa-Bfd) that incorporates a [2Fe-2S]2+/+ center file:PSEAE/bfd/bfd-uniprot.txt PF04324; Fer2_BFD |
| GO:0051537 2 iron, 2 sulfur cluster binding | IDA PMID:17915950 Biochemical and structural characterization of Pseudomonas a... | ACCEPT | Summary: PseudoCAP IDA and a seed of PTN002205442. Spectroscopy of purified Bfd showed a [2Fe-2S] centre. Reason: Seed verdict SOUND; the abstract states the decisive fact outright. Supporting Evidence: PMID:17915950 Biochemical and spectroscopic investigations demonstrated that the bfd gene encodes a 73-amino acid protein (pa-Bfd) that incorporates a [2Fe-2S]2+/+ center |
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Download this section (compressed HTML)Q: Does Bfd transfer electrons directly to the BfrB heme in vivo, and what is its physiological electron donor (FPR or another reductase)?
Experiment: Stopped-flow measurement of electron transfer from reduced Bfd to the BfrB heme, with FPR/NADPH as donor, comparing wild type and interface mutants that block BfrB-Bfd binding.
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