Summary: Hemagglutinin esterase
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.
Hemagglutinin esterase Provide feedback
No Pfam abstract.
Internal database links
|Similarity to PfamA using HHSearch:||Hema_HEFG|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR007142
Haemagglutinin-esterase fusion glycoprotein (HEF) is a multi-functional protein embedded in the viral envelope of several viruses, including influenza C virus, coronaviruses and toroviruses [PUBMED:16575523, PUBMED:9817207]. HEF is required for infectivity, and functions to recognise the host cell surface receptor, to fuse the viral and host cell membranes, and to destroy the receptor upon host cell infection. The haemagglutinin region of HEF is responsible for receptor recognition and membrane fusion, and bears a strong resemblance to the sialic acid-binding haemagglutinin found in influenza A and B viruses, except that it binds 9-O-acetylsialic acid. The esterase region of HEF is responsible for the destruction of the receptor, an action that is carried out by neuraminidase in influenza A and B viruses. The esterase domain is similar in structure to Streptomyces scabies esterase, and to acetylhydrolase, thioesterase I and rhamnogalacturonan acetylesterase.
The haemagglutinin-esterase glycoprotein HEF must be cleaved by the host's trypsin-like proteases to produce two peptides (HEF1 and HEF2) in order for the virus to be infectious. Once HEF is cleaved, the newly exposed N-terminal of the HEF2 peptide then acts to fuse the viral envelope to the cellular membrane of the host cell, which allows the virus to infect the host cell.
The haemagglutinin-esterase glycoprotein is a trimer, where each monomer is composed of three domains: an elongated stem active in membrane fusion, an esterase domain, and a receptor-binding domain, where the stem and receptor-binding domains together resemble influenza A virus haemagglutinin. Two of these domains are composed of non-contiguous sequence: the receptor-binding haemagglutinin domain is inserted into a surface loop of the esterase domain, and the esterase domain is inserted into a surface loop of the haemagglutinin stem.
This entry represents the core of the haemagglutinin-esterase glycoprotein, including the haemagglutinin receptor-binding domain and the esterase domain.
More information about haemagglutinin proteins can be found at Protein of the Month: Bird Flu, Haemagglutinin [PUBMED:].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||viral envelope (GO:0019031)|
|Molecular function||host cell surface receptor binding (GO:0046789)|
|hydrolase activity, acting on ester bonds (GO:0016788)|
|Biological process||fusion of virus membrane with host plasma membrane (GO:0019064)|
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Loading domain graphics...
This superfamily contains a diversity of hydrolytic enzyme activities.
The clan contains the following 11 members:ALGX DHHW DUF303 DUF459 GSCFA Hema_esterase Lipase_GDSL Lipase_GDSL_2 Lipase_GDSL_3 Lipase_GDSL_lke PC-Esterase
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
You can see the alignments as HTML or in three different sequence viewers:
- Pfam viewer
- an HTML-based viewer that uses DAS to retrieve alignment fragments on request
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
If you find these logos useful in your own work, please consider citing the following article:
Note: You can also download the data file for the tree.
Curation and family details
|Seed source:||Pfam-B_505 (release 5.5)|
|Author:||Finn RD, Marshall M|
|Number in seed:||3|
|Number in full:||464|
|Average length of the domain:||321.20 aa|
|Average identity of full alignment:||44 %|
|Average coverage of the sequence by the domain:||75.93 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null --hand HMM SEED
search method: hmmsearch -Z 80369284 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||11|
|Download:||download the raw HMM for this family|
Weight segments by...
Change the size of the sunburst
selected sequences to HMM
a FASTA-format file
- 0 sequences
- 0 species
How the sunburst is generated
Colouring and labels
Anomalies in the taxonomy tree
Missing taxonomic levels
Unmapped species names
Too many species/sequences
The tree shows the occurrence of this domain across different species. More...
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
There are 5 interactions for this family. More...
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 Hema_esterase domain has been found. There are 23 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.
Loading structure mapping...