Domain Annotation: SCOP Classification SCOP Database (version: 2.0) Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species
A	d3bzea1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Class I MHC, alpha-3 domain	human (Homo sapiens ) [TaxId: 9606 ]
A	d3bzea2	Alpha and beta proteins (a+b)	MHC antigen-recognition domain	MHC antigen-recognition domain	MHC antigen-recognition domain	Class I MHC, alpha-1 and alpha-2 domains	human (Homo sapiens ) [TaxId: 9606 ]
C	d3bzec1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Class I MHC, alpha-3 domain	human (Homo sapiens ) [TaxId: 9606 ]
C	d3bzec2	Alpha and beta proteins (a+b)	MHC antigen-recognition domain	MHC antigen-recognition domain	MHC antigen-recognition domain	Class I MHC, alpha-1 and alpha-2 domains	human (Homo sapiens ) [TaxId: 9606 ]
E	d3bzee1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Class I MHC, alpha-3 domain	human (Homo sapiens ) [TaxId: 9606 ]
E	d3bzee2	Alpha and beta proteins (a+b)	MHC antigen-recognition domain	MHC antigen-recognition domain	MHC antigen-recognition domain	Class I MHC, alpha-1 and alpha-2 domains	human (Homo sapiens ) [TaxId: 9606 ]
G	d3bzeg1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	Class I MHC, alpha-3 domain	human (Homo sapiens ) [TaxId: 9606 ]
G	d3bzeg2	Alpha and beta proteins (a+b)	MHC antigen-recognition domain	MHC antigen-recognition domain	MHC antigen-recognition domain	Class I MHC, alpha-1 and alpha-2 domains	human (Homo sapiens ) [TaxId: 9606 ]
B	d3bzeb2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	beta2-microglobulin	human (Homo sapiens ) [TaxId: 9606 ]
B	d3bzeb3	Artifacts	Tags	Tags	Tags	N-terminal Tags	human (Homo sapiens ) [TaxId: 9606 ]
D	d3bzed2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	beta2-microglobulin	human (Homo sapiens ) [TaxId: 9606 ]
D	d3bzed3	Artifacts	Tags	Tags	Tags	N-terminal Tags	human (Homo sapiens ) [TaxId: 9606 ]
F	d3bzef2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	beta2-microglobulin	human (Homo sapiens ) [TaxId: 9606 ]
F	d3bzef3	Artifacts	Tags	Tags	Tags	N-terminal Tags	human (Homo sapiens ) [TaxId: 9606 ]
H	d3bzeh2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	beta2-microglobulin	human (Homo sapiens ) [TaxId: 9606 ]
H	d3bzeh3	Artifacts	Tags	Tags	Tags	N-terminal Tags	human (Homo sapiens ) [TaxId: 9606 ]

Domain Annotation: CATH CATH Database (version 4.2.0) Homepage

Chain	Domain	Class	Architecture	Topology	Homology
A	3.30.500.10	Alpha Beta	2-Layer Sandwich	Murine Class I Major Histocompatibility Complex, H2-DB	Chain A, domain 1
A	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
C	3.30.500.10	Alpha Beta	2-Layer Sandwich	Murine Class I Major Histocompatibility Complex, H2-DB	Chain A, domain 1
C	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
E	3.30.500.10	Alpha Beta	2-Layer Sandwich	Murine Class I Major Histocompatibility Complex, H2-DB	Chain A, domain 1
E	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
G	3.30.500.10	Alpha Beta	2-Layer Sandwich	Murine Class I Major Histocompatibility Complex, H2-DB	Chain A, domain 1
G	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
B	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
D	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
F	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins
H	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Identifier	Description	Comments	Source
A, C, E, G	PF00129	Class I Histocompatibility antigen, domains alpha 1 and 2 (MHC_I)	Class I Histocompatibility antigen, domains alpha 1 and 2	-	Domain
A, C, E, G	PF06623	MHC_I C-terminus (MHC_I_C)	MHC_I C-terminus	-	Family
A, C, E, G	PF07654	Immunoglobulin C1-set domain (C1-set)	Immunoglobulin C1-set domain	-	Domain
B, D, F, H	PF07654	Immunoglobulin C1-set domain (C1-set)	Immunoglobulin C1-set domain	-	Domain
I, J, K, L	PF00129	Class I Histocompatibility antigen, domains alpha 1 and 2 (MHC_I)	Class I Histocompatibility antigen, domains alpha 1 and 2	-	Domain
I, J, K, L	PF07654	Immunoglobulin C1-set domain (C1-set)	Immunoglobulin C1-set domain	-	Domain

Gene Product Annotation Gene Product Annotation

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, C, E, G	HLA class I histocompatibility antigen, alpha chain E	binding protein binding beta-2-microglobulin binding signaling receptor binding MHC protein binding MHC class I protein binding natural killer cell lectin-like receptor binding antigen binding amide binding peptide binding peptide antigen binding T cell receptor binding protein-containing complex binding	viral process biological process involved in symbiotic interaction biological process involved in interspecies interaction between organisms	cell surface cellular anatomical entity intracellular anatomical structure cytoplasm endosome early endosome endosome membrane endomembrane system membrane organelle membrane cytoplasmic vesicle early endosome membrane vesicle organelle membrane-bounded organelle intracellular vesicle bounding membrane of organelle vesicle membrane ER to Golgi transport vesicle membrane transport vesicle COPII-coated ER to Golgi transport vesicle coated vesicle transport vesicle membrane cytoplasmic vesicle membrane coated vesicle membrane plasma membrane external side of plasma membrane cell periphery side of membrane extracellular region extracellular space extracellular organelle extracellular exosome extracellular vesicle endoplasmic reticulum endoplasmic reticulum membrane integral component of membrane integral component of endoplasmic reticulum membrane intrinsic component of membrane intrinsic component of endoplasmic reticulum membrane intrinsic component of organelle membrane integral component of organelle membrane organelle subcompartment nuclear outer membrane-endoplasmic reticulum membrane network intracellular organelle intracellular membrane-bounded organelle integral component of lumenal side of endoplasmic reticulum membrane lumenal side of endoplasmic reticulum membrane lumenal side of membrane endoplasmic reticulum subcompartment protein-containing complex MHC protein complex MHC class I protein complex membrane protein complex plasma membrane protein complex MHC class Ib protein complex endocytic vesicle endocytic vesicle membrane phagocytic vesicle membrane phagocytic vesicle recycling endosome recycling endosome membrane
B, D, F, H	Beta-2-microglobulin	binding protein binding identical protein binding protein homodimerization activity protein dimerization activity	cellular process response to inorganic substance response to metal ion response to iron ion response to chemical response to stimulus cellular response to stimulus cellular response to chemical stimulus cellular response to inorganic substance cellular response to metal ion cellular response to iron ion response to iron(III) ion cellular response to iron(III) ion response to nicotine cellular response to nicotine homeostatic process chemical homeostasis ion homeostasis metal ion homeostasis iron ion homeostasis transition metal ion homeostasis cation homeostasis biological regulation regulation of biological quality inorganic ion homeostasis cell population proliferation negative regulation of cell population proliferation regulation of cell population proliferation negative regulation of biological process negative regulation of cellular process epithelial cell proliferation regulation of epithelial cell proliferation negative regulation of epithelial cell proliferation regulation of biological process regulation of cellular process negative regulation of protein binding regulation of protein binding negative regulation of molecular function regulation of binding negative regulation of binding regulation of molecular function regulation of receptor binding negative regulation of receptor binding positive regulation of molecular function positive regulation of binding regulation of ferrous iron binding positive regulation of ferrous iron binding positive regulation of protein binding positive regulation of receptor binding regulation of transferrin receptor binding positive regulation of transferrin receptor binding cellular component organization cellular component assembly protein-containing complex subunit organization cellular component biogenesis protein complex oligomerization protein homooligomerization protein tetramerization protein homotetramerization protein-containing complex assembly cellular component organization or biogenesis viral process biological process involved in symbiotic interaction biological process involved in interspecies interaction between organisms regulation of defense response to virus by virus response to cadmium ion response to drug	intracellular anatomical structure cytoplasm cytosol cellular anatomical entity endosome early endosome endomembrane system cytoplasmic vesicle endosome lumen early endosome lumen membrane-enclosed lumen vesicle organelle membrane-bounded organelle intracellular organelle organelle lumen intracellular organelle lumen intracellular vesicle endosome membrane membrane organelle membrane early endosome membrane bounding membrane of organelle endoplasmic reticulum endoplasmic reticulum lumen intracellular membrane-bounded organelle vesicle membrane ER to Golgi transport vesicle membrane transport vesicle COPII-coated ER to Golgi transport vesicle coated vesicle transport vesicle membrane cytoplasmic vesicle membrane coated vesicle membrane plasma membrane external side of plasma membrane cell surface cell periphery side of membrane extracellular region extracellular space extracellular organelle extracellular exosome extracellular vesicle focal adhesion cell junction cell-substrate junction anchoring junction Golgi apparatus protein-containing complex receptor complex membrane protein complex plasma membrane protein complex plasma membrane signaling receptor complex HFE-transferrin receptor complex endoplasmic reticulum membrane integral component of membrane integral component of endoplasmic reticulum membrane intrinsic component of membrane intrinsic component of endoplasmic reticulum membrane intrinsic component of organelle membrane integral component of organelle membrane organelle subcompartment nuclear outer membrane-endoplasmic reticulum membrane network MHC class I peptide loading complex endoplasmic reticulum subcompartment endoplasmic reticulum protein-containing complex MHC protein complex MHC class I protein complex endocytic vesicle endocytic vesicle membrane phagocytic vesicle membrane phagocytic vesicle recycling endosome recycling endosome membrane secretory granule vesicle lumen secretory granule lumen specific granule lumen specific granule cytoplasmic vesicle lumen secretory vesicle tertiary granule tertiary granule lumen
P, Q, R, S	leader peptide of HLA class I histocompatibility antigen, alpha chain G	signaling receptor binding binding protein binding CD8 receptor binding identical protein binding antigen binding amide binding peptide binding peptide antigen binding protein homodimerization activity protein dimerization activity	cellular process cellular component organization cellular component assembly protein-containing complex subunit organization cellular component biogenesis protein complex oligomerization protein homooligomerization protein-containing complex assembly protein trimerization protein homotrimerization cellular component organization or biogenesis	intracellular anatomical structure cytoplasm Golgi apparatus cis-Golgi network endomembrane system membrane organelle membrane cis-Golgi network membrane organelle membrane-bounded organelle intracellular organelle intracellular membrane-bounded organelle bounding membrane of organelle cellular anatomical entity endosome early endosome cytoplasmic vesicle vesicle intracellular vesicle endosome membrane early endosome membrane vesicle membrane ER to Golgi transport vesicle membrane transport vesicle COPII-coated ER to Golgi transport vesicle coated vesicle transport vesicle membrane cytoplasmic vesicle membrane coated vesicle membrane plasma membrane external side of plasma membrane cell surface cell periphery side of membrane extracellular region extracellular space filopodium cell projection membrane filopodium membrane cell projection plasma membrane region actin-based cell projection plasma membrane bounded cell projection endoplasmic reticulum endoplasmic reticulum membrane integral component of membrane integral component of endoplasmic reticulum membrane intrinsic component of membrane intrinsic component of endoplasmic reticulum membrane intrinsic component of organelle membrane integral component of organelle membrane organelle subcompartment nuclear outer membrane-endoplasmic reticulum membrane network integral component of lumenal side of endoplasmic reticulum membrane lumenal side of endoplasmic reticulum membrane lumenal side of membrane endoplasmic reticulum subcompartment protein-containing complex MHC protein complex MHC class I protein complex membrane protein complex plasma membrane protein complex endocytic vesicle endocytic vesicle membrane phagocytic vesicle membrane phagocytic vesicle recycling endosome recycling endosome membrane

RCSB PDB is funded by the National Science Foundation (DBI-1832184), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.