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46  structures 2828  species 4  interactions 9173  sequences 30  architectures

Family: ETF (PF01012)

Summary: Electron transfer flavoprotein domain

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This is the Wikipedia entry entitled "Electron-transferring flavoprotein". More...

Electron-transferring flavoprotein Edit Wikipedia article

Electron transfer flavoprotein domain
PDB 1efp EBI.jpg
electron transfer flavoprotein (etf) from paracoccus denitrificans
Identifiers
Symbol ETF
Pfam PF01012
Pfam clan CL0039
InterPro IPR014730
PROSITE PDOC00583
SCOP 1efv
SUPERFAMILY 1efv
Electron transfer flavoprotein FAD-binding domain
PDB 1o96 EBI.jpg
structure of electron transferring flavoprotein for methylophilus methylotrophus.
Identifiers
Symbol ETF_alpha
Pfam PF00766
Pfam clan CL0085
InterPro IPR014731
PROSITE PDOC00583
SCOP 1efv
SUPERFAMILY 1efv

An electron transfer flavoprotein (ETF) is a flavoprotein and functions as a specific electron acceptor for primary dehydrogenases, transferring the electrons to terminal respiratory systems such as electron-transferring-flavoprotein dehydrogenase. They can be functionally classified into constitutive, "housekeeping" ETFs, mainly involved in the oxidation of fatty acids (Group I), and ETFs produced by some prokaryotes under specific growth conditions, receiving electrons only from the oxidation of specific substrates (Group II).[1]

ETFs are heterodimeric proteins composed of an alpha and beta subunit (ETFA and ETFB), and contain an FAD cofactor and AMP.[2][3] ETF consists of three domains: domains I and II are formed by the N- and C-terminal portions of the alpha subunit, respectively, while domain III is formed by the beta subunit. Domains I and III share an almost identical alpha-beta-alpha sandwich fold, while domain II forms an alpha-beta-alpha sandwich similar to that of bacterial flavodoxins. FAD is bound in a cleft between domains II and III, while domain III binds the AMP molecule. Interactions between domains I and III stabilise the protein, forming a shallow bowl where domain II resides.

Mutation in ETFs can lead to deficiency of passing reducing equivalent of FADH2 to electron transport chain, causing Glutaric acidemia type 2

See also[edit]

References[edit]

  1. ^ Weidenhaupt M, Rossi P, Beck C, Fischer HM, Hennecke H (1996). "Bradyrhizobium japonicum possesses two discrete sets of electron transfer flavoprotein genes: fixA, fixB and etfS, etfL". Arch. Microbiol. 165 (3): 169–78. PMID 8599534. 
  2. ^ Tsai MH, Saier MH (1995). "Phylogenetic characterization of the ubiquitous electron transfer flavoprotein families ETF-alpha and ETF-beta". Res. Microbiol. 146 (5): 397–404. doi:10.1016/0923-2508(96)80285-3. PMID 8525056. 
  3. ^ Roberts DL, Frerman FE, Kim JJ (1996). "Three-dimensional structure of human electron transfer flavoprotein to 2.1-A resolution". Proc. Natl. Acad. Sci. U.S.A. 93 (25): 14355–60. doi:10.1073/pnas.93.25.14355. PMC 26136. PMID 8962055. 

External links[edit]

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.

Electron transfer flavoprotein domain Provide feedback

This family includes the homologous domain shared between the alpha and beta subunits of the electron transfer flavoprotein [1].

Literature references

  1. Roberts DL, Frerman FE, Kim JJ; , Proc Natl Acad Sci U S A 1996;93:14355-14360.: Three-dimensional structure of human electron transfer flavoprotein to 2.1-A resolution. PUBMED:8962055 EPMC:8962055


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR014730

Electron transfer flavoproteins (ETFs) serve as specific electron acceptors for primary dehydrogenases, transferring the electrons to terminal respiratory systems. They can be functionally classified into constitutive, "housekeeping" ETFs, mainly involved in the oxidation of fatty acids (Group I), and ETFs produced by some prokaryotes under specific growth conditions, receiving electrons only from the oxidation of specific substrates (Group II) [PUBMED:8599534].

ETFs are heterodimeric proteins composed of an alpha and beta subunit, and contain an FAD cofactor and AMP [PUBMED:2326318, PUBMED:8525056, PUBMED:8962055, PUBMED:10026281, PUBMED:12567183]. ETF consists of three domains: domains I and II are formed by the N- and C-terminal portions of the alpha subunit, respectively, while domain III is formed by the beta subunit. Domains I and III share an almost identical alpha-beta-alpha sandwich fold, while domain II forms an alpha-beta-alpha sandwich similar to that of bacterial flavodoxins. FAD is bound in a cleft between domains II and III, while domain III binds the AMP molecule. Interactions between domains I and III stabilise the protein, forming a shallow bowl where domain II resides.

This entry represents the N-terminal domain of both the alpha and beta subunits from Group I and Group II ETFs.

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 HUP (CL0039), which has the following description:

The HUP class contains the HIGH-signature proteins, UspA superfamily and the PP-ATPase superfamily [1]. The HIGH superfamily has the HIGH Nucleotidyl transferases and the class I tRNA synthetases both of which have the HIGH and the KMSKS motif [1],[2]. The PP-loop ATPase named after the ATP PyroPhosphatase domain, was initially identified as a conserved amino acid sequence motif in four distinct groups of enzymes that catalyse the hydrolysis of the alpha-beta phosphate bond of ATP, namely GMP synthetases, argininosuccinate synthetases, asparagine synthetases, and ATP sulfurylases [3]. The USPA superfamily contains USPA, ETFP and Photolyases [1]

The clan contains the following 26 members:

Arginosuc_synth Asn_synthase ATP-sulfurylase ATP_bind_3 ATP_bind_4 Citrate_ly_lig CTP_transf_2 DNA_photolyase ETF FAD_syn HIGH_NTase1 NAD_synthase Pantoate_ligase PAPS_reduct QueC ThiI tRNA-synt_1 tRNA-synt_1_2 tRNA-synt_1b tRNA-synt_1c tRNA-synt_1d tRNA-synt_1e tRNA-synt_1f tRNA-synt_1g tRNA_Me_trans Usp

Alignments

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 using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

  Seed
(174)
Full
(9173)
Representative proteomes NCBI
(6583)
Meta
(4289)
RP15
(863)
RP35
(1630)
RP55
(2135)
RP75
(2509)
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

  Seed
(174)
Full
(9173)
Representative proteomes NCBI
(6583)
Meta
(4289)
RP15
(863)
RP35
(1630)
RP55
(2135)
RP75
(2509)
Alignment:
Format:
Order:
Sequence:
Gaps:
Download/view:

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

  Seed
(174)
Full
(9173)
Representative proteomes NCBI
(6583)
Meta
(4289)
RP15
(863)
RP35
(1630)
RP55
(2135)
RP75
(2509)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

Pfam alignments:

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

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.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Pfam-B_1321 (release 3.0)
Previous IDs: ETF_beta;
Type: Domain
Author: Bateman A
Number in seed: 174
Number in full: 9173
Average length of the domain: 156.00 aa
Average identity of full alignment: 22 %
Average coverage of the sequence by the domain: 53.86 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 24.2 24.2
Trusted cut-off 24.4 24.4
Noise cut-off 24.1 24.1
Model length: 164
Family (HMM) version: 16
Download: download the raw HMM for this family

Species distribution

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Interactions

There are 4 interactions for this family. More...

Acyl-CoA_dh_N ETF Pyr_redox_2 ETF_alpha

Structures

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 ETF domain has been found. There are 46 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 seqence.

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