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Crystallin, beta B3
Available structures
PDB Ortholog search: PDBe, RCSB
External IDs OMIM123630 MGI102717 HomoloGene3008 GeneCards: CRYBB3 Gene
RNA expression pattern
PBB GE CRYBB3 207685 at tn.png
More reference expression data
Species Human Mouse
Entrez 1417 12962
Ensembl ENSG00000100053 ENSMUSG00000029352
UniProt P26998 Q9JJU9
RefSeq (mRNA) NM_004076 NM_001159650
RefSeq (protein) NP_004067 NP_001153122
Location (UCSC) Chr 22:
25.6 – 25.6 Mb
Chr 5:
113.08 – 113.08 Mb
PubMed search [1] [2]

Beta-crystallin B3 is a protein that in humans is encoded by the CRYBB3 gene.[1][2]

Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Beta-crystallins, the most heterogeneous, differ by the presence of the C-terminal extension (present in the basic group, none in the acidic group). Beta-crystallins form aggregates of different sizes and are able to self-associate to form dimers or to form heterodimers with other beta-crystallins. This gene, a beta basic group member, is part of a gene cluster with beta-A4, beta-B1, and beta-B2.[2]


  1. ^ Lampi KJ, Ma Z, Shih M, Shearer TR, Smith JB, Smith DL, David LL (Feb 1997). "Sequence analysis of betaA3, betaB3, and betaA4 crystallins completes the identification of the major proteins in young human lens". J Biol Chem 272 (4): 2268–75. doi:10.1074/jbc.272.4.2268. PMID 8999933. 
  2. ^ a b "Entrez Gene: CRYBB3 crystallin, beta B3". 

Further reading[edit]