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Immunoglobulin heavy variable 3-30



Homo sapiens (Human)
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli


V region of the variable domain of immunoglobulin heavy chains that participates in the antigen recognition (PubMed:24600447). Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:22158414, PubMed:20176268). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:20176268, PubMed:17576170).4 Publications

GO - Molecular functioni

  • antigen binding Source: UniProtKB
  • serine-type endopeptidase activity Source: Reactome

GO - Biological processi


Biological processAdaptive immunity, Immunity

Enzyme and pathway databases

ReactomeiR-HSA-166663. Initial triggering of complement.
R-HSA-173623. Classical antibody-mediated complement activation.
R-HSA-198933. Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell.
R-HSA-202733. Cell surface interactions at the vascular wall.
R-HSA-2029481. FCGR activation.
R-HSA-2029482. Regulation of actin dynamics for phagocytic cup formation.
R-HSA-2029485. Role of phospholipids in phagocytosis.
R-HSA-2168880. Scavenging of heme from plasma.
R-HSA-2454202. Fc epsilon receptor (FCERI) signaling.
R-HSA-2730905. Role of LAT2/NTAL/LAB on calcium mobilization.
R-HSA-2871796. FCERI mediated MAPK activation.
R-HSA-2871809. FCERI mediated Ca+2 mobilization.
R-HSA-2871837. FCERI mediated NF-kB activation.
R-HSA-5690714. CD22 mediated BCR regulation.
R-HSA-977606. Regulation of Complement cascade.
R-HSA-983695. Antigen activates B Cell Receptor (BCR) leading to generation of second messengers.

Protein family/group databases


Names & Taxonomyi

Protein namesi
Recommended name:
Immunoglobulin heavy variable 3-302 Publications
Alternative name(s):
Ig heavy chain V-III region BUR1 Publication
Ig heavy chain V-III region CAM1 Publication
Ig heavy chain V-III region GA1 Publication
Ig heavy chain V-III region NIE1 Publication
Gene namesi
Name:IGHV3-302 Publications
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
  • UP000005640 Componenti: Chromosome 14

Organism-specific databases

HGNCiHGNC:5591. IGHV3-30.

Subcellular locationi

GO - Cellular componenti

  • extracellular region Source: Reactome
  • extracellular space Source: UniProtKB
  • plasma membrane Source: Reactome

Keywords - Cellular componenti

Cell membrane, Membrane, Secreted

Pathology & Biotechi

Organism-specific databases


Chemistry databases


Polymorphism and mutation databases


PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 194 PublicationsAdd BLAST19
ChainiPRO_000005991920 – 117Immunoglobulin heavy variable 3-304 PublicationsAdd BLAST98

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei20Pyrrolidone carboxylic acid4 Publications1
Disulfide bondi41 ↔ 115PROSITE-ProRule annotation1 Publication

Keywords - PTMi

Disulfide bond, Pyrrolidone carboxylic acid

Proteomic databases



Subunit structurei

Immunoglobulins are composed of two identical heavy chains and two identical light chains; disulfide-linked.1 Publication


3D structure databases


Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini20 – ›117Ig-likePROSITE-ProRule annotationAdd BLAST›98

Keywords - Domaini

Immunoglobulin domain, Immunoglobulin V region, Signal

Phylogenomic databases


Family and domain databases

Gene3Di2.60.40.10. 1 hit.
InterProiView protein in InterPro
IPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR013106. Ig_V-set.
PfamiView protein in Pfam
PF07686. V-set. 1 hit.
SMARTiView protein in SMART
SM00406. IGv. 1 hit.
SUPFAMiSSF48726. SSF48726. 1 hit.
PROSITEiView protein in PROSITE
PS50835. IG_LIKE. 1 hit.


Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P01768-1 [UniParc]FASTAAdd to basket

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60 70 80 90 100
Mass (Da):12,947
Last modified:October 5, 2016 - v2

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti22Q → E AA sequence (PubMed:6774332).Curated1
Sequence conflicti25E → Q AA sequence (PubMed:826475).Curated1
Sequence conflicti30V → A AA sequence (PubMed:4208843).Curated1
Sequence conflicti33 – 35PGR → AGT AA sequence (PubMed:107164).Curated3
Sequence conflicti42A → T AA sequence (PubMed:107164).Curated1
Sequence conflicti45 – 50GFTFSS → AFNLSD AA sequence (PubMed:107164).Curated6
Sequence conflicti47T → S AA sequence (PubMed:4208843).Curated1
Sequence conflicti50 – 53SYGM → RYTI AA sequence (PubMed:826475).Curated4
Sequence conflicti50S → N AA sequence (PubMed:6774332).Curated1
Sequence conflicti50S → T AA sequence (PubMed:4208843).Curated1
Sequence conflicti52G → A AA sequence (PubMed:4208843).Curated1
Sequence conflicti52G → A AA sequence (PubMed:6774332).Curated1
Sequence conflicti52G → A AA sequence (PubMed:107164).Curated1
Sequence conflicti59A → P AA sequence (PubMed:6774332).Curated1
Sequence conflicti67 – 68VA → LS AA sequence (PubMed:4208843).Curated2
Sequence conflicti69V → L AA sequence (PubMed:107164).Curated1
Sequence conflicti70I → M AA sequence (PubMed:826475).Curated1
Sequence conflicti73D → G AA sequence (PubMed:107164).Curated1
Sequence conflicti75S → B AA sequence (PubMed:4208843).Curated1
Sequence conflicti75S → B AA sequence (PubMed:6774332).Curated1
Sequence conflicti75S → B AA sequence (PubMed:826475).Curated1
Sequence conflicti77K → T AA sequence (PubMed:107164).Curated1
Sequence conflicti77K → Z AA sequence (PubMed:4208843).Curated1
Sequence conflicti78Y → H AA sequence (PubMed:826475).Curated1
Sequence conflicti81D → A AA sequence (PubMed:4208843).Curated1
Sequence conflicti84K → N AA sequence (PubMed:826475).Curated1
Sequence conflicti84K → R AA sequence (PubMed:107164).Curated1
Sequence conflicti92 – 93DN → ND AA sequence (PubMed:826475).Curated2
Sequence conflicti93N → I AA sequence (PubMed:107164).Curated1
Sequence conflicti98L → M AA sequence (PubMed:4208843).Curated1
Sequence conflicti101Q → E AA sequence (PubMed:4208843).Curated1
Sequence conflicti101Q → N AA sequence (PubMed:826475).Curated1
Sequence conflicti103 – 104NS → KT AA sequence (PubMed:107164).Curated2
Sequence conflicti107A → P AA sequence (PubMed:826475).Curated1
Sequence conflicti107A → T AA sequence (PubMed:107164).Curated1
Sequence conflicti109D → N AA sequence (PubMed:4208843).Curated1
Sequence conflicti117K → R AA sequence (PubMed:6774332).Curated1
Sequence conflicti117K → R AA sequence (PubMed:4208843).Curated1
Sequence conflicti117K → R AA sequence (PubMed:826475).Curated1
Non-terminal residuei1171


There are several alleles. The sequence shown is that of IMGT allele IGHV3-30*18.Curated

Sequence databases

Select the link destinations:
Links Updated
AC245166 Genomic DNA. No translation available.
PIRiA02051. M3HUAM.
A02052. M3HUGA.
A02056. A1HUBR.
A91668. G1HUNI.

Genome annotation databases

EnsembliENST00000603660; ENSP00000474524; ENSG00000270550.
ENST00000633400; ENSP00000488205; ENSG00000282777.

Keywords - Coding sequence diversityi


Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.

Entry informationi

Entry nameiHV330_HUMAN
AccessioniPrimary (citable) accession number: P01768
Secondary accession number(s): A0A0B4J2B7
, P01769, P01770, P01773
Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: October 5, 2016
Last modified: July 5, 2017
This is version 95 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.



For examples of full length immunoglobulin heavy chains (of different isotypes) see AC P0DOX2, AC P0DOX3, AC P0DOX4, AC P0DOX5 and AC P0DOX6.Curated

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Reference proteome


  1. Human chromosome 14
    Human chromosome 14: entries, gene names and cross-references to MIM