C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17560638  65 WCIRVFAGRLGRDSANQVCATHGGVLSGMQNVEEINYIVSqsvrLISPEVSGGVWVGARRRPacissgitatctKTNSFY 144
Cdd:cd00037   1 SCYKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLAS----LLKKSSSSDVWIGLNDLS------------SEGTWK 64

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 17560638 145 WTDISaTGINGMLFTDGEPNNGAaalDQDCAlltvastplVMNAFRTGQMDDVPCTWQdprpssdkanKGYVCGK 219
Cdd:cd00037  65 WSDGS-PLVDYTNWAPGEPNPGG---SEDCV---------VLSSSSDGKWNDVSCSSK----------LPFICEK 116

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17560638  65 WCIRVFAGRLGRDSANQVCATHGGVLSGMQNVEEINYIVSqsvrLISPEVSGGVWVGARRRPacissgitatctKTNSFY 144
Cdd:cd00037   1 SCYKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLAS----LLKKSSSSDVWIGLNDLS------------SEGTWK 64

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 17560638 145 WTDISaTGINGMLFTDGEPNNGAaalDQDCAlltvastplVMNAFRTGQMDDVPCTWQdprpssdkanKGYVCGK 219
Cdd:cd00037  65 WSDGS-PLVDYTNWAPGEPNPGG---SEDCV---------VLSSSSDGKWNDVSCSSK----------LPFICEK 116

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17560638  65 WCIRVFAGRLGRDSANQVCATHGGVLSGMQNVEEINYIVSqsvrLISPEVSGGVWVGARRRPacissgitatctKTNSFY 144
Cdd:cd00037   1 SCYKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLAS----LLKKSSSSDVWIGLNDLS------------SEGTWK 64

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 17560638 145 WTDISaTGINGMLFTDGEPNNGAaalDQDCAlltvastplVMNAFRTGQMDDVPCTWQdprpssdkanKGYVCGK 219
Cdd:cd00037  65 WSDGS-PLVDYTNWAPGEPNPGG---SEDCV---------VLSSSSDGKWNDVSCSSK----------LPFICEK 116

C-type lectin-like domain (CTLD) of the type found in chondroitin sulfate proteoglycan core proteins; CLECT_CSPGs: C-type lectin-like domain (CTLD) of the type found in chondroitin sulfate proteoglycan core proteins (CSPGs) in human and chicken aggrecan, frog brevican, and zebra fish dermacan. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. In cartilage, aggrecan forms cartilage link protein stabilized aggregates with hyaluronan (HA). These aggregates contribute to the tissue's load bearing properties. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. Xenopus brevican is expressed in the notochord and the brain during early embryogenesis. Zebra fish dermacan is expressed in dermal bones and may play a role in dermal bone development. CSPGs do contain LINK domain(s) which bind HA. These LINK domains are considered by one classification system to be a variety of CTLD, but are omitted from this hierarchical classification based on insignificant sequence similarity.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17560638  51 CDAGWKFFSrpsgGWCIRVFAGRLGRDSANQVCATHGGVLSGMQNVEEINYIVSQSvrlispevSGGVWVGARRRpacis 130
Cdd:cd03588   1 CEEGWDKFQ----GHCYRHFPDRETWEDAERRCREQQGHLSSIVTPEEQEFVNNNA--------QDYQWIGLNDR----- 63

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 17560638 131 sgitatcTKTNSFYWTDIsatgiNGMLF---TDGEPNNGAAAlDQDCalltvastpLVMNAFRTGQMDDVPCTWQDP 204
Cdd:cd03588  64 -------TIEGDFRWSDG-----HPLQFenwRPNQPDNFFAT-GEDC---------VVMIWHEEGEWNDVPCNYHLP 118