Alpha-crystallin domain (ACD) of alpha-crystallin-type small(s) heat shock proteins (Hsps). sHsps are small stress induced proteins with monomeric masses between 12 -43 kDa, whose common feature is the Alpha-crystallin domain (ACD). sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  50 DVLDRDNEIVIRAEVPGMDKEKLDVQVHGNQVYISGSKEEnKTEEEGKYIYRERRYGDFSRTVQLPVDVDASQSKAAYKD 129
Cdd:cd06464     1 DVYETDDAYVVEADLPGFKKEDIKVEVEDGVLTISGEREE-EEEEEENYLRRERSYGSFSRSFRLPEDVDPDKIKASLEN 79

                  ....*....
gi 1775197690 130 GVLELVLPK 138
Cdd:cd06464    80 GVLTITLPK 88

Alpha-crystallin domain (ACD) of alpha-crystallin-type small(s) heat shock proteins (Hsps). sHsps are small stress induced proteins with monomeric masses between 12 -43 kDa, whose common feature is the Alpha-crystallin domain (ACD). sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  50 DVLDRDNEIVIRAEVPGMDKEKLDVQVHGNQVYISGSKEEnKTEEEGKYIYRERRYGDFSRTVQLPVDVDASQSKAAYKD 129
Cdd:cd06464     1 DVYETDDAYVVEADLPGFKKEDIKVEVEDGVLTISGEREE-EEEEEENYLRRERSYGSFSRSFRLPEDVDPDKIKASLEN 79

                  ....*....
gi 1775197690 130 GVLELVLPK 138
Cdd:cd06464    80 GVLTITLPK 88

This domain family includes the alpha-crystallin domain (ACD) of alpha-crystallin-type small heat shock proteins (sHsps) and a similar domain found in p23-like proteins. sHsps are small stress induced proteins with monomeric masses between 12 -43 kDa, whose common feature is this ACD. sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps. p23 is a cochaperone of the Hsp90 chaperoning pathway. It binds Hsp90 and participates in the folding of a number of Hsp90 clients including the progesterone receptor. p23 also has a passive chaperoning activity. p23 in addition may act as the cytosolic prostaglandin E2 synthase. Included in this family is the p23-like C-terminal CHORD-SGT1 (CS) domain of suppressor of G2 allele of Skp1 (Sgt1) and the p23-like domains of human butyrate-induced transcript 1 (hB-ind1), NUD (nuclear distribution) C, Melusin, and NAD(P)H cytochrome b5 (NCB5) oxidoreductase (OR).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  51 VLDRDNEIVIRAEVPGMDKEKLDVQVHGNQVYISGSKEENKTeeegkyiyRERRYGDFSRTVQLPVDVDASQSKAAYKDG 130
Cdd:cd00298     1 WYQTDDEVVVTVDLPGVKKEDIKVEVEDNVLTISGKREEEEE--------RERSYGEFERSFELPEDVDPEKSKASLENG 72

                  ....*...
gi 1775197690 131 VLELVLPK 138
Cdd:cd00298    73 VLEITLPK 80

Alpha crystallin domain (ACD) found in Saccharomyces cerevisiae (Sc) small heat shock protein (Hsp)26 and similar proteins. sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. ScHsp26 is temperature-regulated, it switches from an inactive to a chaperone-active form upon elevation in temperature. It associates into large 24-mers storage forms which upon heat shock disassociate into dimers. These dimers initiate the interaction with non-native substrate proteins and re-assemble into large globular assemblies having one monomer of substrate bound per dimer. This group also contains Arabidopsis thaliana (Ath) Hsp15.7, a peroxisomal matrix protein which can complement the morphological phenotype of S. cerevisiae mutants deficient in Hsps26. AthHsp15.7 is minimally expressed under normal conditions and is strongly induced by heat and oxidative stress. Also belonging to this group is wheat HSP16.9 which differs in quaternary structure from the shell-type particles of ScHsp26, it assembles as a dodecameric double disc, with each disc organized as a trimer of dimers.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  48 HIDVLDRDNEIVIRAEVPGMDKEKLDVQVH-GNQVYISGSKEENKTEEEGKYIYRERRYGDFSRTVQLPVDVDASQSKAA 126
Cdd:cd06472     1 RVDWKETPEAHVFKADVPGVKKEDVKVEVEdGRVLRISGERKKEEEKKGDDWHRVERSSGRFVRRFRLPENADADEVKAF 80

                          90
                  ....*....|..
gi 1775197690 127 YKDGVLELVLPK 138
Cdd:cd06472    81 LENGVLTVTVPK 92

Alpha-crystallin domain (ACD) of metazoan alpha-crystallin-type small(s) heat shock proteins (Hsps). sHsps are small stress induced proteins with monomeric masses between 12 -43 kDa, whose common feature is the Alpha-crystallin domain (ACD). sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  50 DVLDRDNEIVIRAEVPGMDKEKLDVQVHGNQVYISGSKEEnkTEEEGKYIYRErrygdFSRTVQLPVDVDASQSKAAY-K 128
Cdd:cd06526     1 VVNDDDEKFQVTLDVKGFKPEELKVKVSDNKLVVEGKHEE--REDEHGYVSRE-----FTRRYQLPEGVDPDSVTSSLsS 73

                          90
                  ....*....|
gi 1775197690 129 DGVLELVLPK 138
Cdd:cd06526    74 DGVLTIEAPK 83

Alpha-crystallin domain found in the small heat shock protein (sHsp) alphaB-crystallin (HspB5, 20kDa). sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. Alpha crystallin, an abundant protein in the mammalian lens, is a large (700 kDa) heteropolymer composed of HspB4 and HspB5, generally in a molar ratio of HspB4:HspB5 of 3:1. HspB4 does not belong to this group. HspB5 shows increased synthesis in response to stress. HspB5 is also expressed constitutively in other tissues including brain, heart, and type I and type IIa skeletal muscle fibers, and in several cancers including gliomas, renal cell carcinomas, basal-like and metaplastic breast carcinomas, and head and neck cancer. Its functions include effects on the apoptotic pathway and on metastasis. Phosphorylation of HspB5 reduces its oligomerization and anti-apoptotic activities. HspB5 is protective in demyelinating disease such as multiple sclerosis (MS), being a negative regulator of inflammation. In early active MS lesions it is the most abundant gene transcript and an autoantigen, the immune response against it would disrupt its function and worsen inflammation and demyelination. Given as therapy for ongoing demyelinating disease it may counteract this effect. It is an autoantigen in the pathogenesis of various other inflammatory disorders including Lens-associated uveitis (LAU), and Behcet's disease. Mutations in HspB5 have been associated with diseases including dominant cataract and desmin-related myopathy.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  52 LDRDnEIVIRAEVPGMDKEKLDVQVHGNQVYISGSKEENktEEEGKYIYRErrygdFSRTVQLPVDVDA-SQSKAAYKDG 130
Cdd:cd06498     4 LEKD-KFSVNLDVKHFSPEELKVKVLGDFIEIHGKHEER--QDEHGFISRE-----FQRKYRIPADVDPlTITSSLSPDG 75

                  ....*...
gi 1775197690 131 VLELVLPK 138
Cdd:cd06498    76 VLTVCGPR 83

Alpha-crystallin domain found in alphaA-crystallin (HspB4), alphaB-crystallin (HspB5), and the small heat shock protein (sHsp) HspB6, also known as Hsp20. sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. Alpha crystallin, an abundant protein in the mammalian lens, is a large (700 kDa) heteropolymer composed of HspB4 and HspB5, generally in a molar ratio of HspB4:HspB5 of 3:1. Only trace amounts of HspB4 are found in tissues other than the lens. HspB5 on the other hand is also expressed constitutively in other tissues including brain, heart, and type I and type IIa skeletal muscle fibers, and in several cancers including gliomas, renal cell carcinomas, basal-like and metaplastic breast carcinomas, and head and neck cancer. HspB5's functions include effects on the apoptotic pathway and on metastasis. Phosphorylation of HspB5 reduces its oligomerization and anti-apoptotic activities. HspB5 is protective in demyelinating disease such as multiple sclerosis (MS), being a negative regulator of inflammation. In early active MS lesions it is the most abundant gene transcript and an autoantigen, the immune response against it would disrupt its function and worsen inflammation and demyelination. Given as therapy for ongoing demyelinating disease it may counteract this effect. It is an autoantigen in the pathogenesis of various other inflammatory disorders including Lens-associated uveitis (LAU), and Behcet's disease. Mutations in HspB5 have been associated with diseases including dominant cataract and desmin-related myopathy. Mutations in HspB4 have been associated with Autosomal Dominant Congenital Cataract (ADCC). HspB6 (Hsp20) is ubiquitous and is involved in diverse functions including regulation of glucose transport and contraction of smooth muscle, in platelet aggregation, in cardioprotection, and in the prevention of apoptosis. It interacts with the universal scaffolding and adaptor protein 14-3-3, and also with the proapoptotic protein Bax.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1775197690  52 LDRDnEIVIRAEVPGMDKEKLDVQVHGNQVYISGsKEENKTEEEGkYIYRErrygdFSRTVQLPVDVD-ASQSKAAYKDG 130
Cdd:cd06478     4 LDKD-RFSVNLDVKHFSPEELSVKVLGDFVEIHG-KHEERQDEHG-FISRE-----FHRRYRLPPGVDpAAITSSLSADG 75

                  ....*...
gi 1775197690 131 VLELVLPK 138
Cdd:cd06478    76 VLTISGPR 83