Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1). These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development. Neph1 and 2 may mediate axonal guidance and synapse formation in certain areas of the CNS. In the kidney they participate in the formation of the slit diaphragm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 385 GPPIISSTQTQHALHGEKGQIKCFIRSTPPPDRIAWSWKENVLESGTSGRYTVETVSTEEGVISTLTISNIVRADFQTIY 464
Cdd:cd05898     1 GPPIISSEQVQYAVRGERGKVKCFIGSTPPPDRIAWAWKENVLESGTLERYTVERTSTGSGVLSTLTINNIMEADFQTHY 80

                          90
                  ....*....|....*...
gi 2558358145 465 NCTAWNSFGSDTEIIRLK 482
Cdd:cd05898    81 NCTAWNSFGSGTAIIQLE 98

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2558358145 302 PRITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRG---------SGVVLSNEKTLTLKSVRQEDAGKYVCRA 367
Cdd:pfam13927   2 PVITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGepissgstrSRSLSGSNSTLTISNVTRSDAGTYTCVA 76

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2558358145 234 VTFHCSAKANPAVTqYRWAKRGQIIKEASGEVYRTTVDYTYFSEPVS--------CEVTNALGsTNLSRTVDVYFG 301
Cdd:cd05850    23 VTLACRARASPPAT-YRWKMNGTELKMEPDSRYRLVAGNLVISNPVKakdagsyqCLASNRRG-TVVSREASLRFG 96

Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1). These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development. Neph1 and 2 may mediate axonal guidance and synapse formation in certain areas of the CNS. In the kidney they participate in the formation of the slit diaphragm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 385 GPPIISSTQTQHALHGEKGQIKCFIRSTPPPDRIAWSWKENVLESGTSGRYTVETVSTEEGVISTLTISNIVRADFQTIY 464
Cdd:cd05898     1 GPPIISSEQVQYAVRGERGKVKCFIGSTPPPDRIAWAWKENVLESGTLERYTVERTSTGSGVLSTLTINNIMEADFQTHY 80

                          90
                  ....*....|....*...
gi 2558358145 465 NCTAWNSFGSDTEIIRLK 482
Cdd:cd05898    81 NCTAWNSFGSGTAIIQLE 98

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2558358145 302 PRITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRG---------SGVVLSNEKTLTLKSVRQEDAGKYVCRA 367
Cdd:pfam13927   2 PVITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGepissgstrSRSLSGSNSTLTISNVTRSDAGTYTCVA 76

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2558358145 304 ITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRG------SGVVLSNEKTLTLKSVRQEDAGKYVC 365
Cdd:cd20957     4 ATIDPPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGkplghsSRVQILSEDVLVIPSVKREDKGMYQC 71

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 400 GEKGQIKCFIRSTPPPDrIAWSWKENVLESgtSGRYTVetvsTEEGVISTLTISNIVRADfQTIYNCTAWNSFGSDTEII 479
Cdd:pfam07679  15 GESARFTCTVTGTPDPE-VSWFKDGQPLRS--SDRFKV----TYEGGTYTLTISNVQPDD-SGKYTCVATNSAGEAEASA 86

                  ...
gi 2558358145 480 RLK 482
Cdd:pfam07679  87 ELT 89

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145   21 PQDQVVVSGQPVTLLCAIPEY-DGFVLWIKDGLALgvgrdLSSYPQYLVVGNhlSGEHHLKILRAELQDDAVYECQAIQA 99
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSpPPEVTWYKQGGKL-----LAESGRFSVSRS--GSTSTLTISNVTPEDSGTYTCAATNS 73

                           90
                   ....*....|..
gi 2558358145  100 AI-RSRPARLTV 110
Cdd:smart00410  74 SGsASSGTTLTV 85

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145  21 PQDQVVVSGQPVTLLCAI-----PEydgfVLWIKDGLALGVGRdlssypqylvvgNHLSGEHHLKILRAELQDDAVYECQ 95
Cdd:cd05725     4 PQNQVVLVDDSAEFQCEVggdpvPT----VRWRKEDGELPKGR------------YEILDDHSLKIRKVTAGDMGSYTCV 67

                          90
                  ....*....|....*..
gi 2558358145  96 A--IQAAIRSRpARLTV 110
Cdd:cd05725    68 AenMVGKIEAS-ATLTV 83

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2558358145 234 VTFHCSAKANPAVTqYRWAKRGQIIKEASGEVYRTTVDYTYFSEPVS--------CEVTNALGsTNLSRTVDVYFG 301
Cdd:cd05850    23 VTLACRARASPPAT-YRWKMNGTELKMEPDSRYRLVAGNLVISNPVKakdagsyqCLASNRRG-TVVSREASLRFG 96

Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1). These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development. Neph1 and 2 may mediate axonal guidance and synapse formation in certain areas of the CNS. In the kidney they participate in the formation of the slit diaphragm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 385 GPPIISSTQTQHALHGEKGQIKCFIRSTPPPDRIAWSWKENVLESGTSGRYTVETVSTEEGVISTLTISNIVRADFQTIY 464
Cdd:cd05898     1 GPPIISSEQVQYAVRGERGKVKCFIGSTPPPDRIAWAWKENVLESGTLERYTVERTSTGSGVLSTLTINNIMEADFQTHY 80

                          90
                  ....*....|....*...
gi 2558358145 465 NCTAWNSFGSDTEIIRLK 482
Cdd:cd05898    81 NCTAWNSFGSGTAIIQLE 98

Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (also known as Neph1), Kirrel2 (also known as Neph3), and Drosophila RST (also known as irregular chiasm C-roughest) protein. These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 385 GPPIISSTQTQHALHGEKGQIKCFIRSTPPPDRIAWSWKENVLESGTSGRYTVETVSTEEGVISTLTISNIVRADFQTIY 464
Cdd:cd05758     1 GPPIITAEATQPAILGEKARLECLVFSSPPPDRIVWSWDEGFLESGSSGRFSVETFPTEPGVISVLHISGTQRSDFQTSF 80

                          90
                  ....*....|....*...
gi 2558358145 465 NCTAWNSFGSDTEIIRLK 482
Cdd:cd05758    81 NCSAWNRFGEGTAIVSLG 98

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 302 PRITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRGS-------GVVLSNEK--TLTLKSVRQEDAGKYVCRAVVPrV 372
Cdd:pfam07679   1 PKFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQplrssdrFKVTYEGGtyTLTISNVQPDDSGKYTCVATNS-A 79

                          90
                  ....*....|.
gi 2558358145 373 GAGEREVTLTV 383
Cdd:pfam07679  80 GEAEASAELTV 90

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2558358145 304 ITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRG------SGVVLSNEKTLTLKSVRQEDAGKYVC 365
Cdd:cd20957     4 ATIDPPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGkplghsSRVQILSEDVLVIPSVKREDKGMYQC 71

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2558358145 304 ITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRGSGVVLSNEK-------TLTLKSVRQEDAGKYVCRA 367
Cdd:cd20952     2 ILQGPQNQTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERittlengSLQIKGAEKSDTGEYTCVA 72

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 319 AVFSCAWTGNPSLTIVWMKRGSGV---------VLSNEKTLTLKSVRQEDAGKYVCRAVVPRVGAGEREV 379
Cdd:cd00096     1 VTLTCSASGNPPPTITWYKNGKPLppssrdsrrSELGNGTLTISNVTLEDSGTYTCVASNSAGGSASASV 70

Immunoglobulin (Ig) domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig) domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 388 IISSTQTQHALHGEKGQIKCFIRSTPPPdRIAWSWKENVLESGTSGRYTVETVSTEEGVISTLTISNIVRADfQTIYNCT 467
Cdd:cd05735     6 ITSYPNTTLATKGQKKEMSCTAHGEKPI-IVRWEKEDTIINPSEMSRYLVTTKEVGDEVISTLQILPTVRED-SGFFSCH 83

                          90
                  ....*....|....*...
gi 2558358145 468 AWNSFGSDTEIIRLKEQE 485
Cdd:cd05735    84 AINSYGEDRGIIQLTVQE 101

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145  393 QTQHALHGEKGQIKCFIRSTPPPdRIAWSWKENVLeSGTSGRYTVetvsTEEGVISTLTISNiVRADFQTIYNCTAWNSF 472
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPP-EVTWYKQGGKL-LAESGRFSV----SRSGSTSTLTISN-VTPEDSGTYTCAATNSS 74

                           90
                   ....*....|
gi 2558358145  473 GSDTEIIRLK 482
Cdd:smart00410  75 GSASSGTTLT 84

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2558358145 315 LGSDAVFSCAWTGNPSLTIVWMKRGSGVVLSNEK-------TLTLKSVRQEDAGKYVCRaVVPRVGA 374
Cdd:cd05856    18 VGSSVRLKCVASGNPRPDITWLKDNKPLTPPEIGenkkkkwTLSLKNLKPEDSGKYTCH-VSNRAGE 83

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 400 GEKGQIKCFIRSTPPPDrIAWSWKENVLESgtSGRYTVetvsTEEGVISTLTISNIVRADfQTIYNCTAWNSFGSDTEII 479
Cdd:pfam07679  15 GESARFTCTVTGTPDPE-VSWFKDGQPLRS--SDRFKV----TYEGGTYTLTISNVQPDD-SGKYTCVATNSAGEAEASA 86

                  ...
gi 2558358145 480 RLK 482
Cdd:pfam07679  87 ELT 89

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2558358145 307 EPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRGSGVVL--------------SNEKTLTLKSVRQEDAGKYVCRAV 368
Cdd:cd05726     5 KPRDQVVALGRTVTFQCETKGNPQPAIFWQKEGSQNLLfpyqppqpssrfsvSPTGDLTITNVQRSDVGYYICQAL 80

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145  16 SFSQQPQDQVVVSGQPVTLLCAI---PEYDgfVLWIKDglalgvGRDLSSYPQYLVVGNHlsGEHHLKILRAELQDDAVY 92
Cdd:pfam07679   2 KFTQKPKDVEVQEGESARFTCTVtgtPDPE--VSWFKD------GQPLRSSDRFKVTYEG--GTYTLTISNVQPDDSGKY 71

                  ....
gi 2558358145  93 ECQA 96
Cdd:pfam07679  72 TCVA 75

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 303 RITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKrGSGVVLSNEKTLTLKS-------VRQEDAGKYVCRAVVPRVGAG 375
Cdd:cd20968     1 KITRPPTNVTIIEGLKAVLPCTTMGNPKPSVSWIK-GDDLIKENNRIAVLESgslrihnVQKEDAGQYRCVAKNSLGIAY 79

                  ....*...
gi 2558358145 376 EREVTLTV 383
Cdd:cd20968    80 SKPVTIEV 87

Second immunoglobulin (Ig)-like domain of nectin-like molecule-3 (Necl-3); member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin (Ig)-like domain of nectin-like molecule-3 (Necl-3; also known as cell adhesion molecule 2 (CADM2)). Nectin-like molecules have similar domain structures to those of nectins. At least five nectin-like molecules have been identified (Necl-1 through Necl-5). These have an extracellular region containing three Ig-like domains, one transmembrane region, and one cytoplasmic region. Necl-3 has been shown to accumulate in tissues of the central and peripheral nervous system where it is expressed in ependymal cells and myelinated axons. It is observed at the interface between the axon shaft and the myelin sheath. Ig domains are likely to participate in ligand binding and recognition.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 110 VLVPPDDPVILG--GPVISlraGDPLNLTCHADNAKPAASIIWLRKGEVINGATYSKTLLRDGKRESIVSTLFISPGDVE 187
Cdd:cd05884     1 VLGVPEKPQISGftSPVME---GDHIQLTCKTSGSKPAADIRWFKNDKEVKDVKYLKAEDANRKTFTVSSSLDFHVDRDD 77

                          90
                  ....*....|....
gi 2558358145 188 NGQSIVCRATNKAI 201
Cdd:cd05884    78 DGVAITCRVDHESL 91

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2558358145 307 EPQSLLVDLGSDAVFSC-AWTGNPSLTIVWmKRGSGVVLSNEK----TLTLKSVRQEDAGKYVC 365
Cdd:cd05754     7 EPRSQEVRPGADVSFICrAKSKSPAYTLVW-TRVNGTLPSRAMdfngILTIRNVQLSDAGTYVC 69

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 117 PVILGGP-VISLRAGDPLNLTCHADnAKPAASIIWLRKGEVINGATYsktllRDGKRESIVSTLFISPGDVENGQSIVCR 195
Cdd:pfam13927   2 PVITVSPsSVTVREGETVTLTCEAT-GSPPPTITWYKNGEPISSGST-----RSRSLSGSNSTLTISNVTRSDAGTYTCV 75

                  ...
gi 2558358145 196 ATN 198
Cdd:pfam13927  76 ASN 78

CD80-like C2-set immunoglobulin domain; These domains belong to the immunoglobulin superfamily.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 117 PVILGGPVIsLRAGDP-LNLTCHADNAKPAASIIWLRKGEVINGATYSKTLLRDGKRESIVSTLFISPGDVENGQSIVCR 195
Cdd:pfam08205   1 PTIEPPASL-LEGEGPeVVATCSSAGGKPAPRITWYLDGKPLEAAETSSEQDPESGLVTVTSELKLVPSRSDHGQSLTCQ 79

                  ...
gi 2558358145 196 ATN 198
Cdd:pfam08205  80 VSY 82

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 302 PRITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRGSGVVLSNEKT--------LTLKSVRQEDAGKYVCRAvVPRVG 373
Cdd:cd20976     2 PSFSSVPKDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRStceagvgeLHIQDVLPEDHGTYTCLA-KNAAG 80

                          90
                  ....*....|
gi 2558358145 374 AGEREVTLTV 383
Cdd:cd20976    81 QVSCSAWVTV 90

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2558358145 303 RITSEPQSLLVDLGSDAVFSCAWTGNPSLTIVWMKRGS--------GVVLSNEKTLTLKSVRQEDAGKYVCRA 367
Cdd:cd04978     1 YWIIEPPSLVLSPGETGELICEAEGNPQPTITWRLNGVpiepapedMRRTVDGRTLIFSNLQPNDTAVYQCNA 73

Immunoglobulin-like domain of human nephrin and similar proteins; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin-like domain in human nephrin and similar proteins. Nephrin is an integral component of the slit diaphragm and is a central component of the glomerular ultrafilter. Nephrin plays a structural role and has a role in signaling. Nephrin is a transmembrane protein having a short intracellular portion, an extracellular portion comprised of eight Ig-like domains, and one fibronectin type III-like domain. The extracellular portions of nephrin from neighboring foot processes of separate podocyte cells may interact with each other, and in association with other components of the slit diaphragm form a porous molecular sieve within the slit pore. The intracellular portion of nephrin is associated with linker proteins, which connect nephrin to the actin cytoskeleton. The intracellular portion is tyrosine phosphorylated, and mediates signaling from the slit diaphragm into the podocytes.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2558358145 407 CFIRSTPppdRIAWSWKENVLESGTSG-RYTVETVSTEEGVISTLTISNIVRADFQTIYNCTAWNSFGSDTEIIRL 481
Cdd:cd05773    30 CQAQGVP---RVQFRWAKNGVPLDLGNpRYEETTEHTGTVHTSILTIINVSAALDYALFTCTAHNSLGEDSLDIQL 102

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145  16 SFSQQPQDQVVVSGQPVTLLCAIPEYDG-FVLWIKDGLALGVGRDLSSYpqylvvgnHLSGEHHLKILRAELQDDAVYEC 94
Cdd:pfam13927   3 VITVSPSSVTVREGETVTLTCEATGSPPpTITWYKNGEPISSGSTRSRS--------LSGSNSTLTISNVTRSDAGTYTC 74

                  ..
gi 2558358145  95 QA 96
Cdd:pfam13927  75 VA 76

Immunoglobulin C1-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145 110 VLVPPDDPVILGGPVIslragdplnLTCHADNAKPAA-SIIWLRKG-EVINGATYSKTLLRDGKRESIVSTLFISPGDVE 187
Cdd:pfam07654   1 VYVFPPSPEELGKPNT---------LTCLVTGFYPPDiTVTWLKNGqEVTEGVKTTPPSPNSDWTYQLSSYLTVTPSDWE 71

                          90
                  ....*....|...
gi 2558358145 188 NGQSIVCRATNKA 200
Cdd:pfam07654  72 SGDEYTCRVEHEG 84

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2558358145  14 AYSFSQQPQDQVVVSGQPVTLLC-AIPEYDGFVLWIKDGLALGVGRDlSSYPQY----LVVGNHLSGEHHLKilraelqD 88
Cdd:cd05722     1 ELYFLSEPSDIVAMRGGPVVLNCsAESDPPPKIEWKKDGVLLNLVSD-ERRQQLpngsLLITSVVHSKHNKP-------D 72

                          90       100
                  ....*....|....*....|....*
gi 2558358145  89 DAVYECQA---IQAAIRSRPARLTV 110
Cdd:cd05722    73 EGFYQCVAqneSLGSIVSRTARVTV 97