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58  structures 198  species 0  interactions 2456  sequences 2  architectures

Family: HN (PF00423)

Summary: Haemagglutinin-neuraminidase

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This is the Wikipedia entry entitled "Glycoside hydrolase family 83". More...

Glycoside hydrolase family 83 Edit Wikipedia article

Hemagglutinin-neuraminidase
PDB 1usr EBI.jpg
Structure of the sialic acid binding site in Newcastle disease virus hemagglutinin-neuraminidase.[1]
Identifiers
Symbol HN
Pfam PF00423
Pfam clan CL0434
InterPro IPR000665
SCOP 1usr
SUPERFAMILY 1usr

In molecular biology, glycoside hydrolase family 83 is a family of glycoside hydrolases.

Glycoside hydrolases EC 3.2.1. are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families.[2][3][4] This classification is available on the CAZy(http://www.cazy.org/GH1.html) web site,[5] and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.[6]

Glycoside hydrolase family 83 CAZY GH_83 includes enzymes with neuraminidase EC 3.2.1. activity.[7]

References[edit]

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

This is the Wikipedia entry entitled "Hemagglutinin-neuraminidase". More...

Hemagglutinin-neuraminidase Edit Wikipedia article

Hemagglutinin-neuraminidase
PDB 1usr EBI.jpg
Structure of the sialic acid binding site in Newcastle disease virus hemagglutinin-neuraminidase.[1]
Identifiers
Symbol HN
Pfam PF00423
Pfam clan CL0434
InterPro IPR000665
SCOP 1usr
SUPERFAMILY 1usr

Hemagglutinin-neuraminidase refers to a single viral protein that has both hemagglutinin and neuraminidase activity. This is in contrast to the proteins found in influenza, where both functions exist but in two separate proteins.

However it does show a structural similarity to influenza viral neuraminidase and has a six-bladed beta-propeller structure.[2]

Hemagglutinin-neuraminidase allows the virus to stick to a potential host cell, and cut itself loose if necessary.

Hemagglutinin-neuraminidase can be found in a variety of paramyxoviruses including Mumps virus, Human parainfluenza virus 3, and the avian pathogen Newcastle disease virus.

Types include:

Hemagglutinin-neuraminidase inhibitors have been investigated and suggest that there may applications for human use in the future.[3]

References[edit]

  1. ^ Zaitsev V, von Itzstein M, Groves D, et al. (April 2004). "Second sialic acid binding site in Newcastle disease virus hemagglutinin-neuraminidase: implications for fusion". J. Virol. 78 (7): 3733–41. doi:10.1128/JVI.78.7.3733-3741.2004. PMC 371092. PMID 15016893. 
  2. ^ Lawrence MC, Borg NA, Streltsov VA, et al. (January 2004). "Structure of the haemagglutinin-neuraminidase from human parainfluenza virus type III". J. Mol. Biol. 335 (5): 1343–57. doi:10.1016/j.jmb.2003.11.032. PMID 14729348. 
  3. ^ Alymova IV, Taylor G, Takimoto T, et al. (May 2004). "Efficacy of novel hemagglutinin-neuraminidase inhibitors BCX 2798 and BCX 2855 against human parainfluenza viruses in vitro and in vivo". Antimicrob. Agents Chemother. 48 (5): 1495–502. doi:10.1128/AAC.48.5.1495-1502.2004. PMC 400544. PMID 15105096. 

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.

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External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR000665

This entry represents the haemagglutinin-neuraminidase (HN) glycoprotein found in a variety of paramyxoviruses (negative-stranded RNA viruses), including Mumps virus, Human parainfluenza virus 3, and the avian pathogen Newcastle disease virus. The paramyxoviruses have two surface glycoproteins, HN and a fusion protein (F). HN is a multi-functional protein with three distinct functions: a receptor-binding (haemagglutinin) activity, a receptor-destroying (neuraminidase) activity, and a membrane fusion activity that fuses the viral envelope to the host cell membrane in order to infect the cell. The fusion activity involves an interaction between HN and the fusion protein. In other viruses, such as influenza A and B viruses, haemagglutinin and neuraminidase occur as separate glycoproteins.

The haemagglutinin-neuraminidase glycoprotein has a six-bladed beta-propeller structure, and bears structural similarity to influenza A and B virus neuraminidase, bacterial neuraminidase, trypanosomal neuraminidase and transialidase [PUBMED:15016893, PUBMED:14729348].

More information about haemagglutinin proteins can be found at Protein of the Month: Bird Flu, Haemagglutinin [PUBMED:].

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 Sialidase (CL0434), which has the following description:

This superfamily includes sialidases enzymes. Several viruses use sialic acid as a cell surface receptor for host invasion. These viruses then have cell surface neuraminidase enzymes to cleave sialic acid from cell surface proteins allowing them to leave the host cell after replication. This superfamily are composed of six beta-sheets that form a six-fold beta-propeller structure. Many members of this superfamily contain BNR sequence motifs Pfam:PF02012.

The clan contains the following 7 members:

BNR BNR_2 BNR_3 End_beta_propel HN Neur PSII_BNR

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
(21)
Full
(2456)
Representative proteomes NCBI
(2086)
Meta
(0)
RP15
(0)
RP35
(1)
RP55
(1)
RP75
(1)
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Key: ✓ available, x not generated, not available.

Format an alignment

  Seed
(21)
Full
(2456)
Representative proteomes NCBI
(2086)
Meta
(0)
RP15
(0)
RP35
(1)
RP55
(1)
RP75
(1)
Alignment:
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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
(21)
Full
(2456)
Representative proteomes NCBI
(2086)
Meta
(0)
RP15
(0)
RP35
(1)
RP55
(1)
RP75
(1)
Raw Stockholm Download   Download     Download   Download   Download   Download    
Gzipped 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: Pfam-B_171 (release 1.0)
Previous IDs: none
Type: Family
Author: Finn RD
Number in seed: 21
Number in full: 2456
Average length of the domain: 439.80 aa
Average identity of full alignment: 33 %
Average coverage of the sequence by the domain: 94.13 %

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 20.4 20.4
Trusted cut-off 20.5 21.8
Noise cut-off 19.7 20.3
Model length: 549
Family (HMM) version: 14
Download: download the raw HMM for this family

Species distribution

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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 HN domain has been found. There are 58 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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