Structure of the belimumab Fab fragment


Domain Annotation: ECOD Classification ECOD Database Homepage

ChainsFamily NameDomain Identifier ArchitecturePossible HomologyHomologyTopologyFamilyProvenance Source (Version)
B [auth H]V-sete5y9kH1 A: beta barrelsX: FAD-linked reductases, C-terminal domain-likeH: FAD-linked reductases-CT: FAD-linked reductases-CF: V-setECOD (v294.2)
A [auth L]V-sete5y9kL1 A: beta barrelsX: FAD-linked reductases, C-terminal domain-likeH: FAD-linked reductases-CT: FAD-linked reductases-CF: V-setECOD (v294.2)

Domain Annotation: CATH CATH Database Homepage

ChainDomainClassArchitectureTopologyHomologyProvenance Source (Version)
B [auth H]2.60.40.10 Mainly Beta Sandwich Immunoglobulin-like ImmunoglobulinsCATH (4.3.0)
A [auth L]2.60.40.10 Mainly Beta Sandwich Immunoglobulin-like ImmunoglobulinsCATH (4.3.0)

IMGT Antibody Annotation IMGT Database Homepage

ChainProtein NameDescriptionOrganism NameGene Allele Name(s)Domain Name(s)Receptor TypeReceptor DescriptionProvenance Source
B [auth H]Fab belimumab VH-CH1 Homo sapiens (human) IGHV1-69*01, IGHV1-69*12, IGHV1-69*13, IGHV1-69D*01, IGHJ2*01, IGHG1*01, IGHG1*02, IGHG1*04, IGHG1*05, IGHG1*12, IGHG1*14, IGHG1*13, IGHG1*09, IGHG1*10, IGHG1*07, IGHG1*11 V-DOMAIN VH, C-DOMAIN CH1 IG FAB-GAMMA-1_LAMBDA IMGT (202617-0)
A [auth L]Fab belimumab L-LAMBDA Homo sapiens (human) IGLV3-19*01, IGLJ3*02, IGLC2*01, IGLC2*02, IGLC3*04 V-DOMAIN V-LAMBDA, C-DOMAIN C-LAMBDA IG FAB-GAMMA-1_LAMBDA IMGT (202617-0)

SAbDab Antibody Annotation SAbDab Database Homepage

ChainChain ClassChain SubclassChain TypeAntigen Name(s) Provenance Source
B [auth H]Heavy ChainIGHV1 --SAbDab (2026-05-08)
A [auth L]Light ChainIGLV3 Lambda-SAbDab (2026-05-08)

Thera-SAbDab Antibody Annotation Thera-SAbDab Database Homepage

ChainNameTargetProvenance Source
B [auth H] Belimumab TNFSF13B/CD257/BAFFTherapeutic SAbDab (2026-05-08)
A [auth L] Belimumab TNFSF13B/CD257/BAFFTherapeutic SAbDab (2026-05-08)