Alpha crystallin/Hsp20 domain (IPR002068)
Short name: A-crystallin/Hsp20_dom
Overlapping homologous superfamilies
- HSP20-like chaperone (IPR008978)
- Alpha crystallin/Hsp20 domain (IPR002068)
- Alpha-crystallin B chain, ACD domain (IPR037882)
- Heat shock protein beta-1, ACD domain (IPR037876)
- Heat shock protein beta-3 (IPR033894)
- Heat shock protein beta-7, ACD domain (IPR037885)
- Outer dense fibre protein 1, alpha crystallin domain (IPR037552)
- Small heat shock protein IbpA/IbpB, ACD domain (IPR037913)
Prokaryotic and eukaryotic organisms respond to heat shock or other environmental stress by inducing the synthesis of proteins collectively known as heat-shock proteins (hsp) [PMID: 2853609]. Amongst them is a family of proteins with an average molecular weight of 20 Kd, known as the hsp20 proteins [PMID: 7925426]. These seem to act as chaperones that can protect other proteins against heat-induced denaturation and aggregation. Hsp20 proteins seem to form large heterooligomeric aggregates.
These low-molecular-weight proteins are evolutionarily related to alpha-crystallin [PMID: 6285380]. Alpha-crystallin is an abundant constituent of the eye lens of most vertebrate species. Its main function appears to be to maintain the correct refractive index of the lens. It is also found in other tissues where it seems to act as a chaperone [PMID: 7925426]. Other related proteins include certain surface antigens [PMID: 1370952].
This entry represents a conserved C-terminal domain of about 100 residues characteristic of this group of proteins [PMID: 7723051].