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 320545242  51 YFFGTESLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSRlTYWTSGNDLAKTGSHRWFTNAQRISSLRWARNQ 130
Cdd:cd00037    3 YKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLASLLKKSSSS-DVWIGLNDLSSEGTWKWSDGSPLVDYTNWAPGE 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|...
gi 320545242 131 PDNaGQKEHCIHLGYiykdSRKFELNDRPCsqdpNSLFKYICE 173
Cdd:cd00037   82 PNP-GGSEDCVVLSS----SSDGKWNDVSC----SSKLPFICE 115

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 320545242  51 YFFGTESLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSRlTYWTSGNDLAKTGSHRWFTNAQRISSLRWARNQ 130
Cdd:cd00037    3 YKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLASLLKKSSSS-DVWIGLNDLSSEGTWKWSDGSPLVDYTNWAPGE 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|...
gi 320545242 131 PDNaGQKEHCIHLGYiykdSRKFELNDRPCsqdpNSLFKYICE 173
Cdd:cd00037   82 PNP-GGSEDCVVLSS----SSDGKWNDVSC----SSKLPFICE 115

Lectin C-type domain; This family includes both long and short form C-type

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 320545242   57 SLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSRltYWTSGNDLAKTGSHRWfTNAQRISSLRWARNqPDNAGQ 136
Cdd:pfam00059   1 SKTWDEAREACRKLGGHLVSINSAEELDFLSSTLKKSNKY--FWIGLTDRKNEGTWKW-VDGSPVNYTNWAPE-PNNNGE 76

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 320545242  137 KEHCihlGYIYKDSRKfeLNDRPCsqdpNSLFKYICE 173
Cdd:pfam00059  77 NEDC---VELSSSSGK--WNDENC----NSKNPFVCE 104

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 320545242  51 YFFGTESLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSRlTYWTSGNDLAKTGSHRWFTNAQRISSLRWARNQ 130
Cdd:cd00037    3 YKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLASLLKKSSSS-DVWIGLNDLSSEGTWKWSDGSPLVDYTNWAPGE 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|...
gi 320545242 131 PDNaGQKEHCIHLGYiykdSRKFELNDRPCsqdpNSLFKYICE 173
Cdd:cd00037   82 PNP-GGSEDCVVLSS----SSDGKWNDVSC----SSKLPFICE 115

C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR); CLECT_DC-SIGN_like: C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR). This group also contains proteins similar to hepatic asialoglycoprotein receptor (ASGP-R) and langerin in human. These proteins are type II membrane proteins with a CTLD ectodomain. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. DC-SIGN is thought to mediate the initial contact between dendritic cells and resting T cells, and may also mediate the rolling of DCs on epithelium. DC-SIGN and DC-SIGNR bind to oligosaccharides present on human tissues, as well as, on pathogens including parasites, bacteria, and viruses. DC-SIGN and DC-SIGNR bind to HIV enhancing viral infection of T cells. DC-SIGN and DC-SIGNR are homotetrameric, and contain four CTLDs stabilized by a coiled coil of alpha helices. The hepatic ASGP-R is an endocytic recycling receptor which binds and internalizes desialylated glycoproteins having a terminal galactose or N-acetylgalactosamine residues on their N-linked carbohydrate chains, via the clathrin-coated pit mediated endocytic pathway, and delivers them to lysosomes for degradation. It has been proposed that glycoproteins bearing terminal Sia (sialic acid) alpha2, 6GalNAc and Sia alpha2, 6Gal are endogenous ligands for ASGP-R and that ASGP-R participates in regulating the relative concentration of serum glycoproteins bearing alpha 2,6-linked Sia. The human ASGP-R is a hetero-oligomer composed of two subunits, both of which are found within this group. Langerin is expressed in a subset of dendritic leukocytes, the Langerhans cells (LC). Langerin induces the formation of Birbeck Granules (BGs) and associates with these BGs following internalization. Langerin binds, in a calcium-dependent manner, to glyco-conjugates containing mannose and related sugars mediating their uptake and degradation. Langerin molecules oligomerize as trimers with three CTLDs held together by a coiled-coil of alpha helices.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 320545242  47 NDGYYFFGTESLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSrltYWTSGNDLAKTGSHRWFTNAQRISSLR- 125
Cdd:cd03590    9 QSSCYFFSTEKKSWEESRQFCEDMGAHLVIINSQEEQEFISKILSGNRS---YWIGLSDEETEGEWKWVDGTPLNSSKTf 85

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*....
gi 320545242 126 WARNQPDN-AGQKEHCIHLGYIYKDsrkfeLNDRPCSQDpnslFKYICE 173
Cdd:cd03590   86 WHPGEPNNwGGGGEDCAELVYDSGG-----WNDVPCNLE----YRWICE 125

Lectin C-type domain; This family includes both long and short form C-type

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 320545242   57 SLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSRltYWTSGNDLAKTGSHRWfTNAQRISSLRWARNqPDNAGQ 136
Cdd:pfam00059   1 SKTWDEAREACRKLGGHLVSINSAEELDFLSSTLKKSNKY--FWIGLTDRKNEGTWKW-VDGSPVNYTNWAPE-PNNNGE 76

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 320545242  137 KEHCihlGYIYKDSRKfeLNDRPCsqdpNSLFKYICE 173
Cdd:pfam00059  77 NEDC---VELSSSSGK--WNDENC----NSKNPFVCE 104

C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1); CLECT_collectin_like: C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. The CTLDs of these collectins bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, or apoptotic cells) and mediate functions associated with killing and phagocytosis. MBPs recognize high mannose oligosaccharides in a calcium dependent manner, bind to a broad range of pathogens, and trigger cell killing by activating the complement pathway. MBP also acts directly as an opsonin. SP-A and SP-D in addition to functioning as host defense components, are components of pulmonary surfactant which play a role in surfactant homeostasis. Pulmonary surfactant is a phospholipid-protein complex which reduces the surface tension within the lungs. SP-A binds the major surfactant lipid: dipalmitoylphosphatidylcholine (DPPC). SP-D binds two minor components of surfactant that contain sugar moieties: glucosylceramide and phosphatidylinositol (PI). MBP and SP-A, -D monomers are homotrimers with an N-terminal collagen region and three CTLDs. Multiple homotrimeric units associate to form supramolecular complexes. MBL deficiency results in an increased susceptibility to a large number of different infections and to inflammatory disease, such as rheumatoid arthritis.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 320545242  50 YYFFGTESLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSRLtyWTSGNDLAKTGsHRWFTNAQRISSLRWARN 129
Cdd:cd03591    3 IFVTNGEEKNFDDAQKLCSEAGGTLAMPRNAAENAAIASYVKKGNTYA--FIGITDLETEG-QFVYLDGGPLTYTNWKPG 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....
gi 320545242 130 QPDNAGQKEHCihlGYIYKDSrkfELNDRPCsqdpNSLFKYICE 173
Cdd:cd03591   80 EPNNAGGGEDC---VEMYTSG---KWNDVAC----NLTRLFVCE 113

C-type lectin (CTL)/C-type lectin-like (CTLD) domain subgroup 1; a subgroup of protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins; CLECT_1: C-type lectin (CTL)/C-type lectin-like (CTLD) domain subgroup 1; a subgroup of protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. 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. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers from which ligand-binding sites project in different orientations. In some CTLDs a loop extends to the adjoining domain to form a loop-swapped dimer.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 320545242  51 YFFGTESLNWYEAYEKCRELNSELVTFETDQEFDAVTAFLTANGSrlTYWTSgndLAKTGSH-RWfTNAQRISSLRWARN 129
Cdd:cd03602    3 FYLVNESKTWSEAQQYCRENYTDLATVQNQEDNALLSNLSRVSNS--AAWIG---LYRDVDSwRW-SDGSESSFRNWNTF 76

                         90       100
                 ....*....|....*....|..
gi 320545242 130 QPDNagqKEHCihlGYIYKDSR 151
Cdd:cd03602   77 QPFG---QGDC---ATMYSSGR 92

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 320545242  60 WYEAYEKCRELNSELVTFETDQEfdavTAFLTANGSRLTyWTSGNDLAKTGSHRWfTNAQRISSLRWARNQPDN---AGq 136
Cdd:cd03588   22 WEDAERRCREQQGHLSSIVTPEE----QEFVNNNAQDYQ-WIGLNDRTIEGDFRW-SDGHPLQFENWRPNQPDNffaTG- 94

                         90       100
                 ....*....|....*....|....*
gi 320545242 137 kEHCIHLgyIYKDSRKFelNDRPCS 161
Cdd:cd03588   95 -EDCVVM--IWHEEGEW--NDVPCN 114