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PROSITE documentation PDOC00537 [for PROSITE entry PS00615] |
A number of different families of proteins share a conserved domain which was first characterized in some animal lectins and which seem to function as a calcium-dependent carbohydrate-recognition domain [1,2,3]. This domain, which is known as the C-type lectin domain (CTL) or as the carbohydrate-recognition domain (CRD), consists of about 110 to 130 residues. There are four cysteines which are perfectly conserved and involved in two disulfide bonds. A schematic representation of the CTL domain is shown below.
+------+ | | xcxxxxcxxxxxxxCxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxCxxxxWxCxxxxCx | | | ************|* +----+ +-------------------------------------------------+
'C': conserved cysteine involved in a disulfide bond. 'c': optional cysteine involved in a disulfide bond. '*': position of the pattern.
The categories of proteins, in which the CTL domain has been found, are listed below.
Type-II membrane proteins where the CTL domain is located at the C-terminal extremity of the proteins:
Proteins that consist of an N-terminal collagenous domain followed by a CTL-domain [5], these proteins are sometimes called 'collectins':
Selectins (or LEC-CAM) [6,7]. Selectins are cell adhesion molecules implicated in the interaction of leukocytes with platelets or vascular endothelium. Structurally, selectins consist of a long extracellular domain, followed by a transmembrane region and a short cytoplasmic domain. The extracellular domain is itself composed of a CTL-domain, followed by an EGF-like domain and a variable number of SCR/Sushi repeats. Known selectins are:
Large proteoglycans that contain a CTL-domain followed by one copy of a SCR/ Sushi repeat, in their C-terminal section:
In addition to the CTL and Sushi domains, these proteins also contain, in their N-terminal domain, an Ig-like V-type region, two or four link domains (see <PDOC00955>) and up to two EGF-like repeats.
Two type-I membrane proteins:
Various other proteins that uniquely consist of a CTL domain:
As a signature pattern for this domain, we selected the C-terminal region with its three conserved cysteines.
Note:All CTL domains have five Trp residues before the second Cys, with the exception of tunicate lectin and cockroach LPS-BP which have Leu.
Expert(s) to contact by email: Last update:April 2006 / Pattern revised.
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PROSITE methods (with tools and information) covered by this documentation:
1 | Authors | Drickamer K. |
Title | Two distinct classes of carbohydrate-recognition domains in animal lectins. | |
Source | J. Biol. Chem. 263:9557-9560(1988). | |
PubMed ID | 3290208 |
2 | Authors | Drickamer K. |
Title | Evolution of Ca(2+)-dependent animal lectins. | |
Source | Prog. Nucleic Acid Res. Mol. Biol. 45:207-232(1993). | |
PubMed ID | 8341801 |
3 | Authors | Drickamer K. |
Source | Curr. Opin. Struct. Biol. 3:393-400(1993). |
4 | Authors | Spiess M. |
Title | The asialoglycoprotein receptor: a model for endocytic transport receptors. | |
Source | Biochemistry 29:10009-10018(1990). | |
PubMed ID | 2125488 |
5 | Authors | Weis W.I. Kahn R. Fourme R. Drickamer K. Hendrickson W.A. |
Title | Structure of the calcium-dependent lectin domain from a rat mannose-binding protein determined by MAD phasing. | |
Source | Science 254:1608-1615(1991). | |
PubMed ID | 1721241 |
6 | Authors | Siegelman M. |
Title | Sweetening the selectin pot. | |
Source | Curr. Biol. 1:125-128(1991). | |
PubMed ID | 15336187 |
7 | Authors | Lasky L.A. |
Title | Selectins: interpreters of cell-specific carbohydrate information during inflammation. | |
Source | Science 258:964-969(1992). | |
PubMed ID | 1439808 |
8 | Authors | Jomori T. Natori S. |
Title | Molecular cloning of cDNA for lipopolysaccharide-binding protein from the hemolymph of the American cockroach, Periplaneta americana. Similarity of the protein with animal lectins and its acute phase expression. | |
Source | J. Biol. Chem. 266:13318-13323(1991). | |
PubMed ID | 1712779 |
9 | Authors | Ng N.F.L. Hew C.-L. |
Title | Structure of an antifreeze polypeptide from the sea raven. Disulfide bonds and similarity to lectin-binding proteins. | |
Source | J. Biol. Chem. 267:16069-16075(1992). | |
PubMed ID | 1644794 |