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87  structures 3021  species 0  interactions 11095  sequences 255  architectures

Family: FAD_binding_1 (PF00667)

Summary: FAD binding domain

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This is the Wikipedia entry entitled "Flavoprotein pyridine nucleotide cytochrome reductases". More...

Flavoprotein pyridine nucleotide cytochrome reductases Edit Wikipedia article

FAD binding domain

Flavoprotein pyridine nucleotide cytochrome reductases[1] catalyse the interchange of reducing equivalents between one-electron carriers and the two-electron-carrying nicotinamide dinucleotides. The enzymes include ferredoxin-NADP+ reductases,[2] plant and fungal NAD(P)H:nitrate reductases,[1][3] cytochrome b5 reductases,[4] cytochrome P450 reductases,[5] sulphite reductases,[6] nitric oxide synthases,[7] phthalate dioxygenase reductase,[8] and various other flavoproteins.

Human proteins containing this domain



  1. ^ a b Hyde GE, Crawford NM, Campbell WH (1991). "The sequence of squash NADH:nitrate reductase and its relationship to the sequences of other flavoprotein oxidoreductases. A family of flavoprotein pyridine nucleotide cytochrome reductases". J. Biol. Chem. 266 (35): 23542–23547. PMID 1748631.
  2. ^ Karplus PA, Bruns CM (1994). "Structure-function relations for ferredoxin reductase". J. Bioenerg. Biomembr. 26 (1): 89–99. doi:10.1007/BF00763221. PMID 8027025.
  3. ^ Siverio JM (2002). "Assimilation of nitrate by yeasts". FEMS Microbiol. Rev. 26 (3): 277–284. doi:10.1111/j.1574-6976.2002.tb00615.x. PMID 12165428.
  4. ^ Iwanaga S, Miyata T, Yubisui T, Tamura M, Takeshita M (1986). "Complete amino acid sequence of NADH-cytochrome b5 reductase purified from human erythrocytes". J. Biochem. 99 (2): 407–422. PMID 3700359.
  5. ^ Porter TD (1991). "An unusual yet strongly conserved flavoprotein reductase in bacteria and mammals" (PDF). Trends Biochem. Sci. 16 (4): 154–158. doi:10.1016/0968-0004(91)90059-5. PMID 1908607.
  6. ^ Siegel LM, Ostrowski J, Rueger DC, Miller BE, Kredich NM, Barber MJ (1989). "Characterization of the flavoprotein moieties of NADPH-sulfite reductase from Salmonella typhimurium and Escherichia coli. Physicochemical and catalytic properties, amino acid sequence deduced from DNA sequence of cysJ, and comparison with NADPH-cytochrome P-450 reductase". J. Biol. Chem. 264 (27): 15796–15808. PMID 2550423.
  7. ^ Snyder SH, Reed RR, Bredt DS, Hwang PM, Glatt CE, Lowenstein C (1991). "Cloned and expressed nitric oxide synthase structurally resembles cytochrome P-450 reductase". Nature. 351 (6329): 714–718. doi:10.1038/351714a0. PMID 1712077.
  8. ^ Karplus PA, Bruns CM, Correll CC, Ludwig ML (1993). "Structural prototypes for an extended family of flavoprotein reductases: comparison of phthalate dioxygenase reductase with ferredoxin reductase and ferredoxin". Protein Sci. 2 (12): 2112–2133. doi:10.1002/pro.5560021212. PMC 2142325. PMID 8298460.
This article incorporates text from the public domain Pfam and InterPro: IPR003097

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

FAD binding domain Provide feedback

This domain is found in sulfite reductase, NADPH cytochrome P450 reductase, Nitric oxide synthase and methionine synthase reductase.

Literature references

  1. Eschenbrenner M, Coves J, Fontecave M; , J Biol Chem 1995;270:20550-20555.: The flavin reductase activity of the flavoprotein component of sulfite reductase from Escherichia coli. A new model for the protein structure. PUBMED:7657631 EPMC:7657631

  2. Eschenbrenner M, Coves J, Fontecave M; , FEBS Lett 1995;374:82-84.: NADPH-sulfite reductase flavoprotein from Escherichia coli: contribution to the flavin content and subunit interaction. PUBMED:7589518 EPMC:7589518

  3. Smith GC, Tew DG, Wolf CR; , Proc Natl Acad Sci U S A 1994;91:8710-8714.: Dissection of NADPH-cytochrome P450 oxidoreductase into distinct functional domains. PUBMED:8078947 EPMC:8078947

  4. Wang M, Roberts DL, Paschke R, Shea TM, Masters BS, Kim JJ; , Proc Natl Acad Sci U S A 1997;94:8411-8416.: Three-dimensional structure of NADPH-cytochrome P450 reductase: prototype for FMN- and FAD-containing enzymes. PUBMED:9237990 EPMC:9237990

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR003097

This FAD-binding domain can be found in sulfite reductase [NADPH] flavoprotein alpha-component CysJ, NADPH cytochrome P450 reductase, nitric oxide synthase and methionine synthase reductase. CysJ is a component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide [ PUBMED:10860732 ]. The structure of the nitric oxide synthase FAD-binding domain has been solved [ PUBMED:11473123 ].

Gene Ontology

The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan FAD_Lum_binding (CL0076), which has the following description:

Riboflavin nucleotide coenzymes and flavin adenine dinucleotide (FAD) are essential cofactors for a large number of flavoproteins involved in a diverse set of redox reactions. There are thought to be four different FAD-binding folds [1].The FAD-binding fold of this clan is a cylindrical beta-fold. More specifically, the domain forms a flattened six-stranded antiparallel beta-barrel organised into two orthogonal sheets (1-2-5 and 4-3-6) separated by one alpha-helix. The cylinder is open between strands strand 4 and 5. This opening of the cylinder makes space for the isoalloxazine and ribityl moieties of the FAD, to which hydrogen bonds are formed from the open edges of the strands. The other end of the cylinder is covered by the only helix of the domain, which is essential for the binding of the pyrophosphate groups of the FAD [1].The structural differences in the FAD-binding domain are manifested mainly as loops of different length and extra extending structural elements, which may be important for interactions with their redox partners [1]. The structural core of all clan members is highly conserved.

The clan contains the following 5 members:

FAD_binding_1 FAD_binding_6 FAD_binding_8 FAD_binding_9 Lum_binding


We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...

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This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

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Curation and family details

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Curation View help on the curation process

Seed source: Pfam-B_180 (release 2.1)
Previous IDs: FAD_binding;
Type: Domain
Sequence Ontology: SO:0000417
Author: Bateman A
Number in seed: 11
Number in full: 11095
Average length of the domain: 203.00 aa
Average identity of full alignment: 24 %
Average coverage of the sequence by the domain: 25.82 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 57096847 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 32.3 32.3
Trusted cut-off 32.3 32.3
Noise cut-off 32.2 32.2
Model length: 222
Family (HMM) version: 22
Download: download the raw HMM for this family

Species distribution

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Archea Archea Eukaryota Eukaryota
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Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the FAD_binding_1 domain has been found. There are 87 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

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