Summary

Annexin

This family of annexins also includes giardin that has been shown to function as an annexin [1].

Literature references

Bauer B, Engelbrecht S, Bakker-Grunwald T, Scholze H; , FEMS Microbiol Lett 1999;173:147-153.: Functional identification of alpha 1-giardin as an annexin of Giardia lamblia. PUBMED:10220891
Moss SE, Morgan RO; , Genome Biol 2004;5:219.: The annexins. PUBMED:15059252

InterPro entry IPR018502

The annexins (or lipocortins) are a family of proteins that bind to phospholipids in a calcium-dependent manner PUBMED:1646719. They are distributed ubiquitously in different tissues and cell types of higher and lower eukaryotes, including mammals, fish, birds, Drosophila melanogaster (Fruit fly), Xenopus laevis (African clawed frog), Caenorhabditis elegans , Dictyostelium discoideum (Slime mold) and Neurospora crassa PUBMED:9797403, PUBMED:9165068. Annexins are absent from yeasts and prokaryotes PUBMED:15059252. The plant annexins are somewhat distinct from those found in other taxa PUBMED:9165068.

Most eukaryotic species have 1-20 annexin (ANX) genes. All annexins share a core domain made up of four similar repeats, each approximately 70 amino acids long PUBMED:1646719. Each individual annexin repeat (sometimes referred to as endonexin folds) is folded into five alpha-helices, and in turn are wound into a right-handed super-helix; they usually contain a characteristic 'type 2' motif for binding calcium ions with the sequence 'GxGT-[38 residues]-D/E'. Animal and fungal annexins also have variable amino-terminal domains. The core domains of most vertebrate annexins have been analysed by X-ray crystallography, revealing conservation of their secondary and tertiary structures despite only 45-55% amino-acid identity among individual members. The four repeats pack into a structure that resembles a flattened disc, with a slightly convex surface on which the Ca 2+ -binding loops are located and a concave surface at which the amino and carboxyl termini come into close apposition.

Annexins are traditionally thought of as calcium-dependent phospholipid-binding proteins, but recent work suggests a more complex set of functions. The famiy has been linked with inhibition of phospholipase activity, exocytosis and endoctyosis, signal transduction, organisation of the extracellular matrix, resistance to reactive oxygen species and DNA replication PUBMED:9797403.

Gene Ontology

Molecular function	calcium-dependent phospholipid binding (GO:0005544)
	calcium ion binding (GO:0005509)

External database links

HOMSTRAD:	annexin
PANDIT:	PF00191
PRINTS:	PR00196 PR00197 PR00198 PR00199 PR00200 PR00201 PR00202
PROSITE:	PDOC00195
SCOP:	2ran
SYSTERS:	Annexin
Transporter classification:	1.A.31

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

There are various ways to view or download the sequence alignments that we store. You can use a sequence viewer to look at either the seed or full alignment for the family, or you can look at a plain text version of the sequence in a variety of different formats. More...

View options

Alignment:	Seed (180) Full (2919) NCBI (5751) Metagenomics (29)
Viewer:

Formatting options

Alignment:	Seed (180) Full (2919)
Format:
Order:	Tree Alphabetical
Sequence:	Inserts lower case All upper case
Gaps:
Download/view:	Download View

Download options

Very large alignments can often cause problems for the formatting tool above. If you find that downloading or viewing a large alignment is problematic, you can also download a gzip-compressed, Stockholm-format file containing the seed or full alignment for this family.

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

The main seed and full alignments are generated using sequences from the UniProt sequence database. However, we also generate alignments using sequences from the NCBI sequence database and the "metaseq" metagenomics dataset.

You can view alignments from these two additional datasets using the form above, or you can download alignments of NCBI or metagenomics sequences, as gzip-compressed files.

Pfam alignments:	Seed (180) Full (2919) NCBI (5751) Metagenomics (29)
Full length sequences	Full-sequences (2919)

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 HMMER2.

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. 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 or full alignments.

Note: You can also download the data files for the seed, full, NCBI or metagenomics trees.

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

Seed source:

Prosite

Previous IDs:

annexin;

Type:

Family

Author:

Finn RD

Number in seed:

180

Number in full:

2919

Average length of the domain:

64.70 aa

Average identity of full alignment:

29 %

Average coverage of the sequence by the domain:

17.79 %

HMM information

HMM build commands:

build method: hmmbuild -o /dev/null HMM SEED

search method: hmmsearch -Z 9421015 -E 1000 HMM pfamseq

Model details:

Parameter	Sequence	Domain
Gathering cut-off	20.9	20.9
Trusted cut-off	21.7	20.9
Noise cut-off	20.8	20.8

Model length:

66

Family (HMM) version:

13

Download:

download the raw HMM for this family

Species distribution

Tree controls

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

Species trees

We show the species tree in one of two ways. For smaller trees we try to show an interactive representation, which allows you to select specific nodes in the tree and view them as an alignment or as a set of Pfam domain graphics.

Unfortunately we have found that there are problems viewing the interactive tree when the it becomes larger than a certain limit. Furthermore, we have found that Internet Explorer can become unresponsive when viewing some trees, regardless of their size. We therefore show a text representation of the species tree when the size is above a certain limit or if you are using Internet Explorer to view the site.

If you are using IE you can still load the interactive tree by clicking the "Generate interactive tree" button, but please be aware of the potential problems that the interactive species tree can cause.

Interactive tree

For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.

We also count the number of unique sequences on which each domain is found, which is shown in green. Note that a domain may appear multiple times on the same sequence, leading to the difference between these two numbers.

Finally, we group sequences from the same organism according to the NCBI code that is assigned by UniProt, allowing us to count the number of distinct sequences on which the domain is found. This value is shown in the pink boxes.

We use the NCBI species tree to group organisms according to their taxonomy and this forms the structure of the displayed tree. Note that in some cases the trees are too large (have too many nodes) to allow us to build an interactive tree, but in most cases you can still view the tree in a plain text, non-interactive representation. Those species which are represented in the seed alignment for this domain are highlighted.

You can use the tree controls to manipulate how the interactive tree is displayed:

show/hide the summary boxes
highlight species that are represented in the seed alignment
expand/collapse the tree or expand it to a given depth
select a sub-tree or a set of species within the tree and view them graphically or as an alignment
save a plain text representation of the tree

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Interactions

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

Annexin

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 MSD 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 Annexin domain has been found.

Loading structure mapping...

Family: Annexin (PF00191)

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Summary

Annexin

Literature references

InterPro entry IPR018502

Gene Ontology

External database links

Domain organisation

Alignments

Viewing

Downloading

View options

Formatting options

Download options

External links

HMM logo

Trees

Curation and family details

Curation

HMM information

Species distribution

Tree controls

Annotation

Download tree

Selected sequences

Species trees

Interactive tree

Interactions

Structures