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39  structures 249  species 1  interaction 1816  sequences 29  architectures

Family: Apolipoprotein (PF01442)

Summary: Apolipoprotein A1/A4/E domain

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.

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.

Apolipoprotein A1/A4/E domain Provide feedback

These proteins contain several 22 residue repeats which form a pair of alpha helices. This family includes: P02647 Apolipoprotein A-I. P06727 Apolipoprotein A-IV. P02649 Apolipoprotein E.

Literature references

  1. Wilson C, Wardell MR, Weisgraber KH, Mahley RW, Agard DA; , Science 1991;252:1817-1822.: Three-dimensional structure of the LDL receptor-binding domain of human apolipoprotein E. PUBMED:2063194 EPMC:2063194


Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR000074

Exchangeable apolipoproteins (apoA, apoC and apoE) have the same genomic structure and are members of a multi-gene family that probably evolved from a common ancestral gene. This entry includes the ApoA1, ApoA4 and ApoE proteins. ApoA1 and ApoA4 are part of the APOA1/C3/A4/A5 gene cluster on chromosome 11 [PUBMED:15108119]. Apolipoproteins function in lipid transport as structural components of lipoprotein particles, cofactors for enzymes and ligands for cell-surface receptors. In particular, apoA1 is the major protein component of high-density lipoproteins; apoA4 is thought to act primarily in intestinal lipid absorption; and apoE is a blood plasma protein that mediates the transport and uptake of cholesterol and lipid by way of its high affinity interaction with different cellular receptors, including the low-density lipoprotein (LDL) receptor. Recent findings with apoA1 and apoE suggest that the tertiary structures of these two members of the human exchangeable apolipoprotein gene family are related [PUBMED:15234552]. The three-dimensional structure of the LDL receptor-binding domain of apoE indicates that the protein forms an unusually elongated four-helix bundle that may be stabilised by a tightly packed hydrophobic core that includes leucine zipper-type interactions and by numerous salt bridges on the mostly charged surface. Basic amino acids important for LDL receptor binding are clustered into a surface patch on one long helix [PUBMED:2063194].

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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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...

View options

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
(46)
Full
(1816)
Representative proteomes NCBI
(1765)
Meta
(2)
RP15
(146)
RP35
(285)
RP55
(400)
RP75
(715)
Jalview View  View  View  View  View  View  View  View 
HTML View  View  View  View  View  View     
PP/heatmap 1 View  View  View  View  View     
Pfam viewer View  View             

1Cannot generate PP/Heatmap alignments for seeds; no PP data available

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

Format an alignment

  Seed
(46)
Full
(1816)
Representative proteomes NCBI
(1765)
Meta
(2)
RP15
(146)
RP35
(285)
RP55
(400)
RP75
(715)
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
(46)
Full
(1816)
Representative proteomes NCBI
(1765)
Meta
(2)
RP15
(146)
RP35
(285)
RP55
(400)
RP75
(715)
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.

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: Prodom_1521 (release 99.1)
Previous IDs: none
Type: Domain
Author: Bateman A
Number in seed: 46
Number in full: 1816
Average length of the domain: 196.40 aa
Average identity of full alignment: 12 %
Average coverage of the sequence by the domain: 86.35 %

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 90.0 5.0
Trusted cut-off 90.0 5.9
Noise cut-off 89.9 -1000000.0
Model length: 202
Family (HMM) version: 13
Download: download the raw HMM for this family

Species distribution

Sunburst controls

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This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

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Tree controls

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The tree shows the occurrence of this domain across different species. More...

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Interactions

There is 1 interaction for this family. More...

Apolipoprotein

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 Apolipoprotein domain has been found. There are 39 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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