HLA-B

Protein identityUniProt · HPA

UniProt accession

P01889

Gene

HLA-B

Ensembl

ENSG00000234745

Chromosome

6

Canonical length

362 aa

Protein class

Cancer-related genes, Disease related genes, Human disease related genes, Predicted intracellular proteins, Predicted membrane proteins

Quaternary structure

Homodimer

OverviewNCBI Gene

HLA-B belongs to the HLA class I heavy chain paralogues. This class I molecule is a heterodimer consisting of a heavy chain and a light chain (beta-2 microglobulin). The heavy chain is anchored in the membrane. Class I molecules play a central role in the immune system by presenting peptides derived from the endoplasmic reticulum lumen. They are expressed in nearly all cells. The heavy chain is approximately 45 kDa and its gene contains 8 exons. Exon 1 encodes the leader peptide, exon 2 and 3 encode the alpha1 and alpha2 domains, which both bind the peptide, exon 4 encodes the alpha3 domain, exon 5 encodes the transmembrane region and exons 6 and 7 encode the cytoplasmic tail. Polymorphisms within exon 2 and exon 3 are responsible for the peptide binding specificity of each class one molecule. Typing for these polymorphisms is routinely done for bone marrow and kidney transplantation. Hundreds of HLA-B alleles have been described. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

362 residues, UniProt reviewed canonical sequence.

>P01889|HLA-B
     1  MLVMAPRTVL LLLSAALALT ETWAGSHSMR YFYTSVSRPG RGEPRFISVG YVDDTQFVRF
    61  DSDAASPREE PRAPWIEQEG PEYWDRNTQI YKAQAQTDRE SLRNLRGYYN QSEAGSHTLQ
   121  SMYGCDVGPD GRLLRGHDQY AYDGKDYIAL NEDLRSWTAA DTAAQITQRK WEAAREAEQR
   181  RAYLEGECVE WLRRYLENGK DKLERADPPK THVTHHPISD HEATLRCWAL GFYPAEITLT
   241  WQRDGEDQTQ DTELVETRPA GDRTFQKWAA VVVPSGEEQR YTCHVQHEGL PKPLTLRWEP
   301  SSQSTVPIVG IVAGLAVLAV VVIGAVVAAV MCRRKSSGGK GGSYSQAACS DSAQGSDVSL
   361  TA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HLA-B can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Cell surface

Secreted

No

Transmembrane segments

1

Mean surface accessibility (rSASA)

0.37

Highest tissue expression

2,350 nTPM

Expression across tissuesHPA

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about HLA-B.

Disease | AllUniProt

Conditions HLA-B is implicated in, by any mechanism.

• Stevens-Johnson syndrome (SJS) MIM:608579
• Spondyloarthropathy 1 (SPDA1) MIM:106300

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 115 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

• EBV-positive nodal T- and NK-cell lymphoma

Disease | ImmuneIEDB

Conditions an epitope on HLA-B was assayed in.

• autoimmune uveitis T cell
• type 1 diabetes mellitus T cell
• viral infectious disease T cell
• ankylosing spondylitis T cell
• rheumatoid arthritis T cell
• Behcet's disease T cell
• Lyme disease T cell

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

0.91

gnomAD pLI

0

gnomAD missense Z

-0.01

DepMap mean gene effect

-0.01

DepMap dependency class

selective

OntologyGO

Biological processes

• adaptive immune response
• antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-independent
• antigen processing and presentation of endogenous peptide antigen via MHC class Ib
• defense response
• detection of bacterium
• immune response
• innate immune response
• positive regulation of T cell mediated cytotoxicity
• protection from natural killer cell mediated cytotoxicity
• regulation of dendritic cell differentiation
• regulation of interleukin-12 production
• regulation of interleukin-6 production
• regulation of T cell anergy

Molecular functions

• peptide antigen binding
• protein-folding chaperone binding
• signaling receptor binding
• TAP binding

Cellular components

• cell surface
• early endosome membrane
• endoplasmic reticulum
• ER to Golgi transport vesicle membrane
• external side of plasma membrane
• extracellular exosome
• extracellular space
• Golgi apparatus
• Golgi membrane
• lumenal side of endoplasmic reticulum membrane
• membrane
• MHC class I protein complex
• phagocytic vesicle membrane
• plasma membrane
• recycling endosome membrane
• secretory granule membrane

Protein domainsUniProt · Pfam · InterPro

• MHC class I alpha chain, alpha1 alpha2 domains
• Immunoglobulin/major histocompatibility complex, conserved site
• Immunoglobulin C1-set
• Immunoglobulin-like domain
• MHC class I, alpha chain, C-terminal
• MHC class I-like antigen recognition-like
• MHC classes I/II-like antigen recognition protein
• Immunoglobulin-like fold
• Immunoglobulin-like domain superfamily
• MHC class I-like antigen recognition-like superfamily
• Antigen-presenting and immune regulatory MHC class I-related
• Class I Histocompatibility antigen, domains alpha 1 and 2
• MHC_I C-terminus
• Immunoglobulin C1-set domain

KeywordsUniProt

• Adaptive immunity
• Cell membrane
• Disulfide bond
• Endoplasmic reticulum
• Glycoprotein
• Host-virus interaction
• Immunity
• Innate immunity
• Membrane
• MHC I
• Phosphoprotein
• Signal
• Transmembrane
• Transmembrane helix

InteractionsUniProt · HPA

Protein binding partners of HLA-B in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• CALR
• KIR2DL3
• TAP1-TAP2
• TAPBPL
• TCR
• B2M
• HLA-C