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Conserved domains on  [gi|201021269|ref|NP_001013255|]
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B-lymphocyte antigen CD19 precursor [Rattus norvegicus]

Protein Classification

immunoglobulin domain-containing family protein( domain architecture ID 34076)

immunoglobulin (Ig) domain-containing family protein is a member of a large superfamily containing cell surface antigen receptors, co-receptors and co-stimulatory molecules of the immune system, molecules involved in antigen presentation to lymphocytes, cell adhesion molecules, certain cytokine receptors and intracellular muscle proteins; immunoglobulin domains are typically divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets

Graphical summary

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List of domain hits

 Name Accession Description Interval E-value
CD19_protodomain_1_2 cd23999
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 ...
 24-115 5.31e-45

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 and 2; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 1 and 2 of the CD19 double Ig domain.


:

Pssm-ID: 467826  Cd Length: 92  Bit Score: 153.73  E-value: 5.31e-45
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269  24 LLVEVEEGDNVVLSCLRDSSPVSSEKLAWYRGNQSTPFLELSLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLCQKRPSF 103
Cdd:cd23999    1 LLVEVEEGDNAVLPCLIGPSDGPPEQLTWSRGGQLEPFLQLSLGSPGLGAQVGPLGIWLFIFNVSEQMGGFYLCELGPPS 80

                         90
                 ....*....|..
gi 201021269 104 KDTWQPAWTVNV 115
Cdd:cd23999   81 KQAWQPGWTVSV 92
CD19_double_Ig super family cl49627
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, ...
 183-272 1.96e-36

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding.


The actual alignment was detected with superfamily member cd23998:

Pssm-ID: 483967  Cd Length: 95  Bit Score: 130.69  E-value: 1.96e-36
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269 183 QDLTVAPGSTLWLSCGVPPVPVTKGSISWTHVHPKTLNVSLLSLSLGGEHPVREMWV-----WGSLLLLPQAKASDEGTY 257
Cdd:cd23998    1 QDLTVAPGSTLWLSCGVPPDSGTRGPISWTHVHPKPSNTSLLSLELKEDRPAREKWVlgtlrGGALLLLPRATAQDAGIY 80

                         90
                 ....*....|....*
gi 201021269 258 YCLQGGLTIKMHVKV 272
Cdd:cd23998   81 HCHLGNRTISMELTV 95
 
Name Accession Description Interval E-value
CD19_protodomain_1_2 cd23999
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 ...
 24-115 5.31e-45

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 and 2; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 1 and 2 of the CD19 double Ig domain.


Pssm-ID: 467826  Cd Length: 92  Bit Score: 153.73  E-value: 5.31e-45
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269  24 LLVEVEEGDNVVLSCLRDSSPVSSEKLAWYRGNQSTPFLELSLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLCQKRPSF 103
Cdd:cd23999    1 LLVEVEEGDNAVLPCLIGPSDGPPEQLTWSRGGQLEPFLQLSLGSPGLGAQVGPLGIWLFIFNVSEQMGGFYLCELGPPS 80

                         90
                 ....*....|..
gi 201021269 104 KDTWQPAWTVNV 115
Cdd:cd23999   81 KQAWQPGWTVSV 92
CD19_protodomain_3_4 cd23998
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 3 ...
 183-272 1.96e-36

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 3 and 4; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 3 and 4 of the CD19 double Ig domain.


Pssm-ID: 467825  Cd Length: 95  Bit Score: 130.69  E-value: 1.96e-36
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269 183 QDLTVAPGSTLWLSCGVPPVPVTKGSISWTHVHPKTLNVSLLSLSLGGEHPVREMWV-----WGSLLLLPQAKASDEGTY 257
Cdd:cd23998    1 QDLTVAPGSTLWLSCGVPPDSGTRGPISWTHVHPKPSNTSLLSLELKEDRPAREKWVlgtlrGGALLLLPRATAQDAGIY 80

                         90
                 ....*....|....*
gi 201021269 258 YCLQGGLTIKMHVKV 272
Cdd:cd23998   81 HCHLGNRTISMELTV 95
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
 183-259 4.05e-05

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


Pssm-ID: 214653 [Multi-domain]  Cd Length: 85  Bit Score: 42.11  E-value: 4.05e-05
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269   183 QDLTVAPGSTLWLSCGVPPVPVTkgSISWTHVHPKTLNvsllslslggeHPVREMWVWGSL---LLLPQAKASDEGTYYC 259
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPP--EVTWYKQGGKLLA-----------ESGRFSVSRSGStstLTISNVTPEDSGTYTC 68
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
 26-115 8.33e-04

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


Pssm-ID: 214653 [Multi-domain]  Cd Length: 85  Bit Score: 38.64  E-value: 8.33e-04
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269    26 VEVEEGDNVVLSCLRDSSPVSSekLAWYRGNqstpfLELSLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLCQKRPSFKD 105
Cdd:smart00410   4 VTVKEGESVTLSCEASGSPPPE--VTWYKQG-----GKLLAESGRFSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSGS 76

                           90
                   ....*....|
gi 201021269   106 TWQPAwTVNV 115
Cdd:smart00410  77 ASSGT-TLTV 85
Ig_3 pfam13927
Immunoglobulin domain; This family contains immunoglobulin-like domains.
 182-259 3.16e-03

Immunoglobulin domain; This family contains immunoglobulin-like domains.


Pssm-ID: 464046 [Multi-domain]  Cd Length: 78  Bit Score: 36.77  E-value: 3.16e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269  182 NQDLTVAPGSTLWLSCGV--PPVPvtkgSISWTHVHPKTLNVSLLSLSLGGEhpvremwvwGSLLLLPQAKASDEGTYYC 259
Cdd:pfam13927   8 PSSVTVREGETVTLTCEAtgSPPP----TITWYKNGEPISSGSTRSRSLSGS---------NSTLTISNVTRSDAGTYTC 74
Ig_3 pfam13927
Immunoglobulin domain; This family contains immunoglobulin-like domains.
 26-98 4.41e-03

Immunoglobulin domain; This family contains immunoglobulin-like domains.


Pssm-ID: 464046 [Multi-domain]  Cd Length: 78  Bit Score: 36.39  E-value: 4.41e-03
                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 201021269   26 VEVEEGDNVVLSCLRDSSPvsSEKLAWYRGNQSTPFLELSLRSPDLGlhigplGILLVIVNVSDHRGGFYLCQ 98
Cdd:pfam13927  11 VTVREGETVTLTCEATGSP--PPTITWYKNGEPISSGSTRSRSLSGS------NSTLTISNVTRSDAGTYTCV 75
 
Name Accession Description Interval E-value
CD19_protodomain_1_2 cd23999
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 ...
 24-115 5.31e-45

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 and 2; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 1 and 2 of the CD19 double Ig domain.


Pssm-ID: 467826  Cd Length: 92  Bit Score: 153.73  E-value: 5.31e-45
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269  24 LLVEVEEGDNVVLSCLRDSSPVSSEKLAWYRGNQSTPFLELSLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLCQKRPSF 103
Cdd:cd23999    1 LLVEVEEGDNAVLPCLIGPSDGPPEQLTWSRGGQLEPFLQLSLGSPGLGAQVGPLGIWLFIFNVSEQMGGFYLCELGPPS 80

                         90
                 ....*....|..
gi 201021269 104 KDTWQPAWTVNV 115
Cdd:cd23999   81 KQAWQPGWTVSV 92
CD19_protodomain_3_4 cd23998
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 3 ...
 183-272 1.96e-36

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 3 and 4; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 3 and 4 of the CD19 double Ig domain.


Pssm-ID: 467825  Cd Length: 95  Bit Score: 130.69  E-value: 1.96e-36
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269 183 QDLTVAPGSTLWLSCGVPPVPVTKGSISWTHVHPKTLNVSLLSLSLGGEHPVREMWV-----WGSLLLLPQAKASDEGTY 257
Cdd:cd23998    1 QDLTVAPGSTLWLSCGVPPDSGTRGPISWTHVHPKPSNTSLLSLELKEDRPAREKWVlgtlrGGALLLLPRATAQDAGIY 80

                         90
                 ....*....|....*
gi 201021269 258 YCLQGGLTIKMHVKV 272
Cdd:cd23998   81 HCHLGNRTISMELTV 95
CD19_double_Ig cd23997
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, ...
 24-115 2.83e-32

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding.


Pssm-ID: 467824  Cd Length: 89  Bit Score: 118.98  E-value: 2.83e-32
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269  24 LLVEVEEGDNVVLSCLRDSSPVSSEKLAWYRGNQSTPFLELSLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLCQKRPSf 103
Cdd:cd23997    1 LDVTVAEGSTLWLPCLVPPSDGPRGPLTWSRGHPKTPLLSLELGSPGLWVLVGPLGILLLLPNVSAQMGGFYLCELGNL- 79

                         90
                 ....*....|..
gi 201021269 104 kdTWQPAWTVNV 115
Cdd:cd23997   80 --SWTIGWTVSV 89
CD19_double_Ig cd23997
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, ...
 183-272 4.90e-18

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding.


Pssm-ID: 467824  Cd Length: 89  Bit Score: 78.92  E-value: 4.90e-18
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269 183 QDLTVAPGSTLWLSCGVPPVPVTKGSISWTHVHPKTLNVSLlslslggEHPVREMWV----WGSLLLLPQAKASDEGTYY 258
Cdd:cd23997    1 LDVTVAEGSTLWLPCLVPPSDGPRGPLTWSRGHPKTPLLSL-------ELGSPGLWVlvgpLGILLLLPNVSAQMGGFYL 73

                         90
                 ....*....|....*.
gi 201021269 259 CLQGGL--TIKMHVKV 272
Cdd:cd23997   74 CELGNLswTIGWTVSV 89
Ig_Semaphorin_C cd04979
Immunoglobulin (Ig)-like domain at the C-terminus of semaphorins; The members here are ...
 185-284 6.69e-09

Immunoglobulin (Ig)-like domain at the C-terminus of semaphorins; The members here are composed of the immunoglobulin (Ig)-like domain in semaphorins. Semaphorins are transmembrane protein that have important roles in a variety of tissues. Functionally, semaphorins were initially characterized for their importance in the development of the nervous system and in axonal guidance. Later they have been found to be important for the formation and functioning of the cardiovascular, endocrine, gastrointestinal, hepatic, immune, musculoskeletal, renal, reproductive, and respiratory systems. Semaphorins function through binding to their receptors and transmembrane semaphorins also serves as receptors themselves. Although molecular mechanism of semaphorins is poorly understood, the Ig-like domains may be involved in ligand binding or dimerization.


Pssm-ID: 409368  Cd Length: 88  Bit Score: 52.85  E-value: 6.69e-09
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269 185 LTVAPGSTLWLSCGVPP--VPVTkgsisWTHVHPKtlnvsllslsLGGEHPVREMWVWGSLLLLPQAKASDEGTYYCLQG 262
Cdd:cd04979    6 ISVKEGDTVILSCSVKSnnAPVT-----WIHNGKK----------VPRYRSPRLVLKTERGLLIRSAQEADAGVYECHSG 70

                         90       100
                 ....*....|....*....|..
gi 201021269 263 GLTIkmhvKVIARSAVWLWLLR 284
Cdd:cd04979   71 ERVL----GSTLRSVTLHVLER 88
IgI_1_MuSK cd20970
agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of ...
 20-97 3.80e-06

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). 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.


Pssm-ID: 409562 [Multi-domain]  Cd Length: 92  Bit Score: 45.19  E-value: 3.80e-06
                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 201021269  20 PQNSLLVEVEEGDNVVLSCLRDSSPvsSEKLAWYR-GNQstpflelsLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLC 97
Cdd:cd20970    6 PQPSFTVTAREGENATFMCRAEGSP--EPEISWTRnGNL--------IIEFNTRYIVRENGTTLTIRNIRRSDMGIYLC 74
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
 183-259 4.05e-05

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


Pssm-ID: 214653 [Multi-domain]  Cd Length: 85  Bit Score: 42.11  E-value: 4.05e-05
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269   183 QDLTVAPGSTLWLSCGVPPVPVTkgSISWTHVHPKTLNvsllslslggeHPVREMWVWGSL---LLLPQAKASDEGTYYC 259
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPP--EVTWYKQGGKLLA-----------ESGRFSVSRSGStstLTISNVTPEDSGTYTC 68
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
 26-115 8.33e-04

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


Pssm-ID: 214653 [Multi-domain]  Cd Length: 85  Bit Score: 38.64  E-value: 8.33e-04
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269    26 VEVEEGDNVVLSCLRDSSPVSSekLAWYRGNqstpfLELSLRSPDLGLHIGPLGILLVIVNVSDHRGGFYLCQKRPSFKD 105
Cdd:smart00410   4 VTVKEGESVTLSCEASGSPPPE--VTWYKQG-----GKLLAESGRFSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSGS 76

                           90
                   ....*....|
gi 201021269   106 TWQPAwTVNV 115
Cdd:smart00410  77 ASSGT-TLTV 85
Ig_3 pfam13927
Immunoglobulin domain; This family contains immunoglobulin-like domains.
 182-259 3.16e-03

Immunoglobulin domain; This family contains immunoglobulin-like domains.


Pssm-ID: 464046 [Multi-domain]  Cd Length: 78  Bit Score: 36.77  E-value: 3.16e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 201021269  182 NQDLTVAPGSTLWLSCGV--PPVPvtkgSISWTHVHPKTLNVSLLSLSLGGEhpvremwvwGSLLLLPQAKASDEGTYYC 259
Cdd:pfam13927   8 PSSVTVREGETVTLTCEAtgSPPP----TITWYKNGEPISSGSTRSRSLSGS---------NSTLTISNVTRSDAGTYTC 74
Ig_3 pfam13927
Immunoglobulin domain; This family contains immunoglobulin-like domains.
 26-98 4.41e-03

Immunoglobulin domain; This family contains immunoglobulin-like domains.


Pssm-ID: 464046 [Multi-domain]  Cd Length: 78  Bit Score: 36.39  E-value: 4.41e-03
                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 201021269   26 VEVEEGDNVVLSCLRDSSPvsSEKLAWYRGNQSTPFLELSLRSPDLGlhigplGILLVIVNVSDHRGGFYLCQ 98
Cdd:pfam13927  11 VTVREGETVTLTCEATGSP--PPTITWYKNGEPISSGSTRSRSLSGS------NSTLTISNVTRSDAGTYTCV 75
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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