Seroatlas · Human Serome Atlas

HADHB

Trifunctional enzyme subunit beta, mitochondrial

Also known as: ECHB_HUMAN, MTPB

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P55084
Gene
HADHB
Ensembl
ENSG00000138029
Chromosome
2
Canonical length
474 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted intracellular proteins
Subcellular location
Mitochondria,Equatorial segment,Principal piece

OverviewNCBI Gene

This gene encodes the beta subunit of the mitochondrial trifunctional protein, which catalyzes the last three steps of mitochondrial beta-oxidation of long chain fatty acids. The mitochondrial membrane-bound heterocomplex is composed of four alpha and four beta subunits, with the beta subunit catalyzing the 3-ketoacyl-CoA thiolase activity. The encoded protein can also bind RNA and decreases the stability of some mRNAs. The genes of the alpha and beta subunits of the mitochondrial trifunctional protein are located adjacent to each other in the human genome in a head-to-head orientation. Mutations in this gene result in trifunctional protein deficiency. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2013]

Canonical amino-acid sequenceUniProt

474 residues, UniProt reviewed canonical sequence.

>P55084|HADHB
     1  MTILTYPFKN LPTASKWALR FSIRPLSCSS QLRAAPAVQT KTKKTLAKPN IRNVVVVDGV
    61  RTPFLLSGTS YKDLMPHDLA RAALTGLLHR TSVPKEVVDY IIFGTVIQEV KTSNVAREAA
   121  LGAGFSDKTP AHTVTMACIS ANQAMTTGVG LIASGQCDVI VAGGVELMSD VPIRHSRKMR
   181  KLMLDLNKAK SMGQRLSLIS KFRFNFLAPE LPAVSEFSTS ETMGHSADRL AAAFAVSRLE
   241  QDEYALRSHS LAKKAQDEGL LSDVVPFKVP GKDTVTKDNG IRPSSLEQMA KLKPAFIKPY
   301  GTVTAANSSF LTDGASAMLI MAEEKALAMG YKPKAYLRDF MYVSQDPKDQ LLLGPTYATP
   361  KVLEKAGLTM NDIDAFEFHE AFSGQILANF KAMDSDWFAE NYMGRKTKVG LPPLEKFNNW
   421  GGSLSLGHPF GATGCRLVMA AANRLRKEGG QYGLVAACAA GGQGHAMIVE AYPK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HADHB 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
Other membrane
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.27
Highest tissue expression
1,024 nTPM

Expression across tissuesHPA

Tissue

  • tongue: 1,024 nTPM
  • skeletal muscle: 917 nTPM
  • heart muscle: 749 nTPM
  • liver: 304 nTPM
  • kidney: 216 nTPM
  • adrenal gland: 214 nTPM

Single-cell type

  • esophageal apical cells: 515 nCPM
  • thymic myoid cells: 499 nCPM
  • cardiomyocytes: 477 nCPM
  • enterocytes: 445 nCPM
  • parietal cells: 433 nCPM
  • myonuclei: 362 nCPM

Immune cell

  • classical monocyte: 168 nTPM
  • myeloid DC: 154 nTPM
  • intermediate monocyte: 150 nTPM
  • total PBMC: 136 nTPM
  • non-classical monocyte: 124 nTPM
  • basophil: 96 nTPM

Brain region

  • white matter: 166 nTPM
  • cerebellum: 158 nTPM
  • thalamus: 155 nTPM
  • midbrain: 151 nTPM
  • spinal cord: 148 nTPM
  • medulla oblongata: 142 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about HADHB.

Disease | AllUniProt

Conditions HADHB is implicated in, by any mechanism.

  • Mitochondrial trifunctional protein deficiency 2 (MTPD2) MIM:620300

Disease | GeneticClinVar

100 pathogenic / likely-pathogenic of 639 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
1.04
gnomAD pLI
0
gnomAD missense Z
0.65
DepMap mean gene effect
0.02
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads HADHB as an antibody target. Whether an autoantibody or antibody against HADHB could matter depends on whether native HADHB is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

HADHB is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label HADHB as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/HADHB. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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