NCBI Summary
Ficolins are a group of proteins which consist of a collagen-like domain and a fibrinogen-like domain. In human serum, there are two types of ficolins, both of which have lectin activity. The protein encoded by this gene is a thermolabile beta-2-macroglycoprotein found in all human serum and is a member of the ficolin/opsonin p35 lectin family. The protein, which was initially identified based on its reactivity with sera from patients with systemic lupus erythematosus, has been shown to have a calcium-independent lectin activity. The protein can activate the complement pathway in association with MASPs and sMAP, thereby aiding in host defense through the activation of the lectin pathway. Alternative splicing occurs at this locus and two variants, each encoding a distinct isoform, have been identified. [provided by RefSeq, Jul 2008].
Protein (NP_003656)
Ficolin-3 (Collagen/fibrinogen domain-containing lectin 3 p35) (Collagen/fibrinogen domain-containing protein 3) (Hakata antigen)
ficolin 3
a/b mixed with b-sheet / Fibrinogen C-ter like
Protein sequence and protein families (fasta) (299 amino acids) Download
Mol* PDB structure viewerUniLectin3D
Structural models
Model Confidence:
  •    Very high (pLDDT > 90)
  •    Confident (90 > pLDDT > 70)
  •    Low (70 > pLDDT > 50)
  •    Very low (pLDDT < 50)

  AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Glycan ligands from structural data
NCBI References (10 PubMed Identifiers)
  • FCN3 functions as a tumor suppressor of lung adenocarcinoma through induction of endoplasmic reticulum stress. [33859174]
  • Association of ficolin-1 and ficolin-3 gene variation and pulmonary tuberculosis susceptibility in a Chinese population. [33591573]
  • The clinical value of ficolin-3 gene polymorphism in rheumatic heart disease. An Egyptian adolescents study. [33499929]
  • Associations of ficolins and mannose-binding lectin with acute myeloid leukaemia in adults. [32601370]
  • Circulating Ficolin-2 and Ficolin-3 Form Heterocomplexes. [32094208]
  • Activation of the lectin complement pathway by H-ficolin (Hakata antigen). [11907111]
  • Hakata antigen, a new member of the ficolin/opsonin p35 family, is a novel human lectin secreted into bronchus/alveolus and bile. [10330454]
  • Cloning and characterization of the Hakata antigen, a member of the ficolin/opsonin p35 lectin family. [9694814]
  • Isolation and characterization of a thermolabile beta-2 macroglycoprotein ('thermolabile substance' or 'Hakata antigen') detected by precipitating (auto) antibody in sera of patients with systemic lupus erythematosus. [1859827]
  • Serological studies of an SLE-associated antigen-antibody system discovered as a precipitation reaction in agarose gel: the HAKATA antigen-antibody system. [2276712]
UniProt Main References (9 PubMed Identifiers)
  • Complete sequencing and characterization of 21,243 full-length human cDNAs. [14702039]
  • The DNA sequence and biological annotation of human chromosome 1. [16710414]
  • The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). [15489334]
  • Signal peptide prediction based on analysis of experimentally verified cleavage sites. [15340161]
  • Human plasma N-glycoproteome analysis by immunoaffinity subtraction, hydrazide chemistry, and mass spectrometry. [16335952]
  • Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry. [19159218]
  • A strategy for precise and large scale identification of core fucosylated glycoproteins. [19139490]
  • Immunodeficiency associated with FCN3 mutation and ficolin-3 deficiency. [19535802]
  • Structural insights into the innate immune recognition specificities of L- and H-ficolins. [17215869]
All isoforms of this gene containing a lectin domain
NP_003656.2, NP_775628.1
RNA (Transcript ID: NM_003665.4)
ficolin 3, transcript variant 1
  • Coding region
DNA (Gene ID: 8547)
ficolin 3
strand -
NCBI CDS gene sequence (900 bp)
NCBI CDS gene sequence with introns (location: 27369236.. 27374818) (5583 bp)Download
NCBI CDS gene sequence with introns, 5'UTR and 3'UTR (location: 27369110.. 27374824) (5715 bp)Download
NCBI gene sequence (location: [27369110.. 27374824 + 1000]) (6715 bp)Download
How to cite: Schnider B., M'Rad Y., el Ahmadie J., de Brevern AG., Imberty A., Lisacek F., HumanLectome, an update of UniLectin for the annotation and prediction of human lectins, Nucleic Acids Reasearch