Summary: Extracellular link domain
This is the Wikipedia entry entitled "Xlinkdomain". More...
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Xlinkdomain Edit Wikipedia article
solution structure of the hyaluronan binding domain of human cd44
The Xlink domain functions as a hyaluronan binding domain and is important in blood cell migration and apoptosis.The link domain  is a hyaluronan(HA)-binding region found in proteins of vertebrates that are involved in the assembly of extracellular matrix, cell adhesion, and migration.
The structure has been shown  to consist of two alpha helices and two antiparallel beta sheets arranged around a large hydrophobic core similar to that of C-type lectin. This domain contains four conserved cysteines involved in two disulphide bonds. The link domain has also been termed HABM  (HA binding module) and PTR  (proteoglycan tandem repeat).
Proteins which contain the Xlink domain include:
- the proteoglycans: aggrecan, brevican, neurocan and versican, which are expressed in the CNS;
- the cartilage link protein (LP), a proteoglycan that together with HA and aggrecan forms multimolecular aggregates;
- Tumour necrosis factor-inducible protein TSG-6, which may be involved in cell-cell and cell-matrix interactions during inflammation and tumourgenesis;
- CD44 antigen, the main cell surface receptor for HA.
- Yoneda M, Nakamura T, Murai M, Wada H (2010). "Evidence for the heparin-binding ability of the ascidian Xlink domain and insight into the evolution of the Xlink domain in chordates.". J Mol Evol 71 (1): 51â9. doi:10.1007/s00239-010-9363-x. PMID 20582409.
- Barta E, DeÃÂ¡k F, Kiss I (June 1993). "Evolution of the hyaluronan-binding module of link protein". Biochem. J. 292 (3): 947â9. PMC 1134205. PMID 8318021.
- Kohda D, Morton CJ, Parkar AA, Hatanaka H, Inagaki FM, Campbell ID, Day AJ (September 1996). "Solution structure of the link module: a hyaluronan-binding domain involved in extracellular matrix stability and cell migration". Cell 86 (5): 767â75. doi:10.1016/S0092-8674(00)80151-8. PMID 8797823.
- Brissett NC, Perkins SJ (June 1996). "The protein fold of the hyaluronate-binding proteoglycan tandem repeat domain of link protein, aggrecan and CD44 is similar to that of the C-type lectin superfamily". FEBS Lett. 388 (2-3): 211â6. doi:10.1016/0014-5793(96)00576-5. PMID 8690089.
Extracellular link domain Provide feedback
No Pfam abstract.
Brissett NC, Perkins SJ; , FEBS Lett 1996;388:211-216.: The protein fold of the hyaluronate-binding proteoglycan tandem repeat domain of link protein, aggrecan and CD44 is similar to that of the C-type lectin superfamily. PUBMED:8690089 EPMC:8690089
Internal database links
|SCOOP:||Herpes_UL45 Chordopox_A33R Intimin_C|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR000538The link domain [PUBMED:8318021] is a hyaluronan(HA)-binding region found in proteins of vertebrates that are involved in the assembly of extracellular matrix, cell adhesion, and migration. The structure has been shown [PUBMED:8797823] to consist of two alpha helices and two antiparallel beta sheets arranged around a large hydrophobic core similar to that of C-type lectin. This domain contains four conserved cysteines involved in two disulphide bonds. The link domain has also been termed HABM [PUBMED:8318021] (HA binding module) and PTR [PUBMED:8690089] (proteoglycan tandem repeat). Proteins with such a domain include the proteoglycans aggrecan, brevican, neurocan and versican, which are expressed in the CNS; the cartilage link protein (LP), a proteoglycan that together with HA and aggrecan forms multimolecular aggregates; Tumour necrosis factor-inducible protein TSG-6, which may be involved in cell-cell and cell-matrix interactions during inflammation and tumourgenesis; and CD44 antigen, the main cell surface receptor for HA.
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||hyaluronic acid binding (GO:0005540)|
|Biological process||cell adhesion (GO:0007155)|
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Curation and family details
|Author:||Sonnhammer ELL, Bateman A|
|Number in seed:||12|
|Number in full:||1651|
|Average length of the domain:||93.40 aa|
|Average identity of full alignment:||40 %|
|Average coverage of the sequence by the domain:||15.67 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||12|
|Download:||download the raw HMM for this family|
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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 Xlink domain has been found. There are 14 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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