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 17536863  54 WCMRVFaGFNAKKADAEKSCQAVGSTLSGIQNKNEALYIQTALLAqipQSSGSVWIGIQRTQKClkqkltaacsalTAFE 133
Cdd:cd00037   1 SCYKFS-TEKLTWEEAQEYCRSLGGHLASIHSEEENDFLASLLKK---SSSSDVWIGLNDLSSE------------GTWK 64

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 17536863 134 YTDKSvTGTDGFVFQKYQPDNSQlNQNCALLLASKTptilndqyfaATLDDTNCDgmlegdaarVLRGYICGK 206
Cdd:cd00037  65 WSDGS-PLVDYTNWAPGEPNPGG-SEDCVVLSSSSD----------GKWNDVSCS---------SKLPFICEK 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 17536863  54 WCMRVFaGFNAKKADAEKSCQAVGSTLSGIQNKNEALYIQTALLAqipQSSGSVWIGIQRTQKClkqkltaacsalTAFE 133
Cdd:cd00037   1 SCYKFS-TEKLTWEEAQEYCRSLGGHLASIHSEEENDFLASLLKK---SSSSDVWIGLNDLSSE------------GTWK 64

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 17536863 134 YTDKSvTGTDGFVFQKYQPDNSQlNQNCALLLASKTptilndqyfaATLDDTNCDgmlegdaarVLRGYICGK 206
Cdd:cd00037  65 WSDGS-PLVDYTNWAPGEPNPGG-SEDCVVLSSSSD----------GKWNDVSCS---------SKLPFICEK 116

C-type lectin-like domain (CTLD) of the type found in Human REG-1 (lithostathine), REG-4, and avian eggshell-specific proteins: ansocalcin, structhiocalcin-1(SCA-1), and -2(SCA-2); CLECT_REG-1_like: C-type lectin-like domain (CTLD) of the type found in Human REG-1 (lithostathine), REG-4, and avian eggshell-specific proteins: ansocalcin, structhiocalcin-1(SCA-1), and -2(SCA-2). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. REG-1 is a proliferating factor which participates in various kinds of tissue regeneration including pancreatic beta-cell regeneration, regeneration of intestinal mucosa, regeneration of motor neurons, and perhaps in tissue regeneration of damaged heart. REG-1 may play a role on the pathophysiology of Alzheimer's disease and in the development of gastric cancers. Its expression is correlated with reduced survival from early-stage colorectal cancer. REG-1 also binds and aggregates several bacterial strains from the intestinal flora and it has been suggested that it is involved in the control of the intestinal bacterial ecosystem. Rat lithostathine has calcium carbonate crystal inhibitor activity in vitro. REG-IV is unregulated in pancreatic, gastric, hepatocellular, and prostrate adenocarcinomas. REG-IV activates the EGF receptor/Akt/AP-1 signaling pathway in colorectal carcinoma. Ansocalcin, SCA-1 and -2 are found at high concentration in the calcified egg shell layer of goose and ostrich, respectively and tend to form aggregates. Ansocalcin nucleates calcite crystal aggregates in vitro.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17536863  40 CEPGWKFFNrpsgGWCMRVFagfNAKK--ADAEKSCQAV--GSTLSGIQNKNEALYIqTALLAQIPQSSGSVWIGIQRTQ 115
Cdd:cd03594   1 CPKGWLPYK----GNCYGYF---RQPLswSDAELFCQKYgpGAHLASIHSPAEAAAI-ASLISSYQKAYQPVWIGLHDPQ 72

                .
gi 17536863 116 K 116
Cdd:cd03594  73 Q 73