Lipocalin / cytosolic fatty-acid binding protein family; Lipocalins are transporters for small hydrophobic molecules, such as lipids, steroid hormones, bilins, and retinoids. The family also encompasses the enzyme prostaglandin D synthase (EC:5.3.99.2). Alignment subsumes both the lipocalin and fatty acid binding protein signatures from PROSITE. This is supported on structural and functional grounds. The structure is an eight-stranded beta barrel.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854    34 SGTWYLDSIASDNmTRIEENGDLRLFIRNIKLLNNGSLQFDFHFMLQGECVAVTMVCEKTKNNGEFSV---AYEGKNKVL 110
Cdd:pfam00061   1 SGKWYLIASANFN-ELEEEMKALGVGFATIKVLENGNLPVTEITKEGGKCKTVSVTFKKTEEPGKLGVefdEYAGGRKVK 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 12860854   111 LLETDYSMYIIFYMQNIKNGTKTQVLALYGRSILLDKTHQREFENICNLYGLDSQNIIDMTKKD 174
Cdd:pfam00061  80 VLTTDYDNYLIFYQKGDKDGKTTIVRELYGRDPELSPELLEKFKKFLKELGIDEENIVRLYQKD 143

major urinary proteins (MUPs) and similar proteins; Mouse urine contains major urinary proteins (MUPs) which bind low molecular weight hydrophobic organic compounds such as urinary volatile pheromones such as the male-specific 2-sec-butyl-4,5-dihydrothiazole (SB2HT) which hastens puberty in female mice. The association between MUPs and these volatiles slows the release of the volatiles into the air from urine marks. MUPs may also act as pheromones themselves. MUPs, expressed in the nasal and vomeronasal mucosa, may be important for delivering urinary volatiles to receptors in the vomeronasal organ. This group includes MUPs encoded by central genes in the MUP cluster, as well as those encoded by peripheral genes such as Darcin/Mup20 which binds most of the male pheromone SB2HT in urine and was the first MUP shown to have male pheromonal activity in its own right. This group includes rat MUPs (also called alpha-2U globulins) and other lipocalins such as major horse allergen Equ c 1 and boar salivary lipocalin, a pheromone-binding protein specifically expressed in the submaxillary glands of the boar. It belongs to the lipocalin/cytosolic fatty-acid binding protein family which have a large beta-barrel ligand-binding cavity. Lipocalins are mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules, as well as membrane bound-receptors. They participate in processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty-acid binding proteins, also bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  23 AVRRDYNLARISGTWYLDSIASDNMTRIEENGDLRLFIRNIKLLNNgSLQFDFHFMLQGECVAVTMVCEKTKNNGEFSVA 102
Cdd:cd19428   1 SVTRNFDVSKINGEWYSILLASDKREKIEENGSMRVFVEHIHVLEN-SLAFKFHTKVNGECTELNLVADKTEKAGEYSVT 79

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 12860854 103 YEGKNKVLLLETDYSMYIIFYMQNIKNGTKTQVLALYGRSILLDKTHQREFENICNLYGLDSQNIIDMTKKDFCF 177
Cdd:cd19428  80 YDGYNTFTILETDYDNYIMFHLINFKNGETFQLMELYGREPDVSSDIKERFVKLCEEHGIIKENIIDLTKTDRCL 154

lipocalin/cytosolic fatty acid-binding protein family; Lipocalins are diverse, mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules as well as membrane bound-receptors. They have a large beta-barrel ligand-binding cavity. Members include retinol-binding protein, retinoic acid-binding protein, complement protein C8 gamma, Can f 2, apolipoprotein D, extracellular fatty acid-binding protein, beta-lactoglobulin, oderant-binding protein, and bacterial lipocalin Blc. Lipocalins are involved in many important processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty acid-binding proteins also bind hydrophobic ligands in a non-covalent, reversible manner, and are involved in protection and shuttling of fatty acids within the cell, and in acquisition and removal of fatty acids from intracellular sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  32 RISGTWYLDSIASDNmtriEENGDLRLFIRNIKLLNNGSLQFDFHFMLQGECVAVTMVCEKTKNNGEFSVAYE---GKNK 108
Cdd:cd00301   1 KFSGKWYEVASASNA----PEEDEGKCTTAEYTLEGNGNLKVTNSFVRDGVCKSITGTLKKTDGPGKFTVTYPgytGKNE 76

                        90       100       110
                ....*....|....*....|....*....|...
gi 12860854 109 VLLLETDYSMYIIFYMQNIKNGTKTQVLALYGR 141
Cdd:cd00301  77 LYVLSTDYDNYAIVYSCKNLDGGHTVVAWLLSR 109

beta-lactoglobulin and similar proteins; Beta-Lactoglobulin (beta-LG) is the major whey protein of ruminant species and present in the milk of many other species, with a notable exception of human. It is the major allergen of bovine milk. Beta-LG has been shown to bind hydrophobic ligands such as curcumin, vitamin E or fatty acids, or hydrophilic such as vitamin B9. This group also includes human glycodelin (also known as placental protein 14, pregnancy-associated endometrial alpha-2 globulin, and progestagen-associated endometrial protein) which is involved in crucial biological processes such as reproduction and immune reaction. Four glycoforms of glycodelin have been identified in reproductive tissue that differ in glycosylation and biological activity. This group belongs to the lipocalin/cytosolic fatty-acid binding protein family which have a large beta-barrel ligand-binding cavity. Lipocalins are mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules, as well as membrane bound-receptors. They participate in processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty-acid binding proteins, also bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  22 TAVRRDYNLARISGTWYLDSIASDNMTRIE-ENGDLRLFIRNIKLLNNGSLQFDFHFMLQGECVAVTMVCEKTKNNGEFS 100
Cdd:cd19416   2 TQTMKDLDVQKVAGTWYSLAMAASDISLLDaQSAPLRVYIEELKPTPEGNLEIVLQKWENGRCAEKKLLAEKTKIPAVFK 81

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 12860854 101 VAYEGKNKVLLLETDYSMYIIFYMQNIKNGTKTQVLALYGRSILLDKTHQREFENI 156
Cdd:cd19416  82 INALNENKVLVLDTDYDSYLLFCMENSAEPEQSLACQCLVRTLEVDNEAMEKFDKA 137

extracellular fatty acid-binding protein; Ex-FABP (also known as siderocalin, lipocalin Q83 or protein Ch21) displays a dual ligand binding mode as it can bind siderophore and fatty acids simultaneously. ExFABP has a cavity which extends through the protein and has two separate ligand specificities, one for bacterial siderophores at one end, and other specifically binding co-purified lysophosphatidic acid (LPA), a potent cell signaling molecule, at the other end. As well as acting as an LPA "sensor", Ex-FABP is bacteriostatic, and tightly binds the 2,3-catechol-type ferric siderophores enterobactin, bacillibactin, and parabactin, associated with enteric bacteria and Gram-positive bacilli. This group belongs to the lipocalin/cytosolic fatty-acid binding protein family which have a large beta-barrel ligand-binding cavity. Lipocalins are mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules, as well as membrane bound-receptors. They participate in processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty-acid binding proteins, also bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  32 RISGTWYLDSIASDNMTRIEENGDLRLFIRNIKLLNNGSLQFDFHFMLQGECVAVTMVCEKTKNNGEFSVAYEGKNKVLL 111
Cdd:cd19439   3 ELAGKWYLVALASNTDFFLREKGKMKMMMARISFLGEDELLVSYAFPSPGGCRKWETTFKKTSDDGEVYYSEEARKTVEV 82

                        90       100       110
                ....*....|....*....|....*....|.
gi 12860854 112 LETDYSMYIIFYMQNIKNGTKTQVLALYGRS 142
Cdd:cd19439  83 LDTDYKSYAVIYATRVKDGRTLHMMRLYSRS 113

lipocalin-1, -3, -4, -13 and similar proteins; Lipocalin-1 (LCN1, also known as tear lipocalin, von ebner's gland protein, or tear specific prealbumin), the main lipid carrier in human tears, is critical to functions involving lipids in protection of the ocular surface. Its large ligand pocket accommodates a range of ligands including alkyl alcohols, glycolipids, phospholipids, cholesterol, steroids, and siderophores. Lipocalin-3 (LCN3, also known as vomeronasal secretory protein 1) and lipocalin-4 (LCN4, also known as vomeronasal secretory protein 2) are involved in transport of lipophilic molecules, and are possibly pheromone-carriers. Lipocalin-13 (LCN13, also known as odorant binding protein 2A) may bind and transport small hydrophobic volatile molecules with a higher affinity for aldehydes and large fatty acids. Another member of this family is late lactation protein B (LLPB), a milk protein produced during the late phase of lactation, which may be involved in transporting a small ligand released during the hydrolysis of milk fat. This group belongs to the lipocalin/cytosolic fatty-acid binding protein family which have a large beta-barrel ligand-binding cavity. Lipocalins are mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules, as well as membrane bound-receptors. They participate in processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty-acid binding proteins, also bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  33 ISGTWYLDSIASD-NMTriEENGDLRLFIRNIKLLNNGSLQFDFHFMLQGECVAVTMVCEKTKNNGEFSvAYEGKNKVLL 111
Cdd:cd19414   5 VSGTWYLKAMVVDkEFP--EKRRPRKVSPVTVTALEGGNLEAKFTFMINGRCEEVKIVLEKTDEPGKYT-AFSGKKVVYI 81

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 12860854 112 LETDYSMYIIFYMQNIKNGTKTQVLALYGRSilldkTHQ-----REFENICNLYGLDSQNII 168
Cdd:cd19414  82 QETSVKDHYILYCEGELHGMTFRMAKLVGRD-----PEEnpealEEFKKFVQRKGLNEENIV 138

lipocalin-type prostaglandin D synthase; Lipocalin-type prostaglandin D synthase (L-PGDS; EC:5.3.99.2) is a secreted enzyme and the second most abundant protein in human cerebrospinal fluid. L-PGDS acts as both, an enzyme and as a lipid transporter, converting prostaglandin H2 to prostaglandin D2 and serving as a carrier for hydrophobic ligands including retinoids, hemoglobin metabolites, thyroid hormones, gangliosides, and fatty acids. L-PGDS belongs to the lipocalin/cytosolic fatty-acid binding protein family which has a large beta-barrel ligand-binding cavity. Lipocalins are mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules, as well as membrane bound-receptors. They participate in processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty-acid binding proteins, also bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  24 VRRDYNLARISGTWYLDSIASDNMTRIEENGDLRLFIRNIKLLNNGSLQFDFHFMLQGECVAVTMVCEKTKNNGEF---S 100
Cdd:cd19419   1 PQPDFDLDKFAGRWYSVGLASNSNWFVEKKAKLKMCTTVVAPTTDGNLNLTMTFLKKNGCETRTYLYEKTEQPGRFtykS 80

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 12860854 101 VAYEGKNKVLLLETDYSMYIIFYMQNIKNGTKTQVLALYGRSILLDKTHQREFENICNLYGLDSQNIIDMTKKDFC 176
Cdd:cd19419  81 PRWGSDHDVRVVETNYDEYALVHTIKTKGNEEFTMVTLYSRTQTLRPELKEKFRQFAKAQGFTEENIVTLPQTDEC 156

complement protein C8 gamma; Human complement protein C8 gamma, together with C8alpha and C8beta, form one of five components of the cytolytic membrane attack complex (MAC), a pore-like structure that assembles on bacterial membranes. C8alpha and C8gamma form a disulfide-linked heterodimer that is noncovalently associated with C8beta. MAC plays an important role in the defense against gram-negative bacteria and other pathogenic organisms. C8gamma belongs to the lipocalin/cytosolic fatty-acid binding protein family which have a large beta-barrel ligand-binding cavity. Lipocalins are mainly low molecular weight extracellular proteins that bind principally small hydrophobic ligands, and form covalent or non-covalent complexes with soluble macromolecules, as well as membrane bound-receptors. They participate in processes such as ligand transport, modulation of cell growth and metabolism, regulation of immune response, smell reception, tissue development and animal behavior. Cytosolic fatty-acid binding proteins, also bind hydrophobic ligands in a non-covalent, reversible manner, and have been implicated in intracellular uptake, transport and storage of hydrophobic ligands, regulation of lipid metabolism and sequestration of excess toxic fatty acids, as well as in signaling, gene expression, inflammation, cell growth and proliferation, and cancer development.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 12860854  27 DYNLARISGTWYLDSIASdNMTRIEENGdLRLFIRNIKLLNNG-SLQFDFHFMLQGECVAVTMVCEKTKNNGEFSVAYEG 105
Cdd:cd19417   5 NFDIQQFSGKWYLVAVAS-ACRYLQESG-HKVEATVLTVAPPKtTVAVSTFRKLNGICWEIKQEYGKTGTLGRFLLKARR 82

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 12860854 106 KNK---VLLLETDYSMYIIFYMQNIKNGTktqvLALYGRSILLDKTHQREFENICNLYGLDSQNIIDMTKKDFC 176
Cdd:cd19417  83 PRGntdIVVGETDYSSYAILYYQRAGKLT----MKLYGRSTELSENILDKFEQRAQKAHLGLDQIFYFPKYGFC 152