Small heat shock protein IbpA, HSP20 family [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 116062205  62 VSVDDLGDRLRILIDLPGMDRESLNIVVLEDRVEISARIREHVVKRALGSLSEKFSFREYRGVYRLPAPVDPRSVRIRTR 141
Cdd:COG0071    2 VDIEETDDAYVITADLPGVDKEDIDVTVEGNVLTISGERKEEEEEEGENYLRRERRYGSFERSFTLPDDVDVDKIEASYE 81

                         90
                 ....*....|....
gi 116062205 142 GSLIIVEADKKAAV 155
Cdd:COG0071   82 NGVLTITLPKAEEA 95

Small heat shock protein IbpA, HSP20 family [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 116062205  62 VSVDDLGDRLRILIDLPGMDRESLNIVVLEDRVEISARIREHVVKRALGSLSEKFSFREYRGVYRLPAPVDPRSVRIRTR 141
Cdd:COG0071    2 VDIEETDDAYVITADLPGVDKEDIDVTVEGNVLTISGERKEEEEEEGENYLRRERRYGSFERSFTLPDDVDVDKIEASYE 81

                         90
                 ....*....|....
gi 116062205 142 GSLIIVEADKKAAV 155
Cdd:COG0071   82 NGVLTITLPKAEEA 95

Hsp20/alpha crystallin family; Not only do small heat-shock-proteins occur in eukaryotes and prokaryotes but they have also now been shown to occur in cyanobacterial phages as well as their bacterial hosts.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 116062205   69 DRLRILIDLPGMDRESLNIVVLEDRVEISArIREHVVKRALGSLSEkFSFREYRGVYRLPAPVDPRSVRIRTRGSLIIVE 148
Cdd:pfam00011   7 DAFEVRLDVPGFKPEELKVKVEDNRLLVKG-EHEEEKEDDHGLRSE-RSYGSFSRKFTLPENADPDKVKASLKDGVLTVT 84

                  ....*..
gi 116062205  149 ADKKAAV 155
Cdd:pfam00011  85 VPKLEPE 91

Small heat shock protein IbpA, HSP20 family [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 116062205  62 VSVDDLGDRLRILIDLPGMDRESLNIVVLEDRVEISARIREHVVKRALGSLSEKFSFREYRGVYRLPAPVDPRSVRIRTR 141
Cdd:COG0071    2 VDIEETDDAYVITADLPGVDKEDIDVTVEGNVLTISGERKEEEEEEGENYLRRERRYGSFERSFTLPDDVDVDKIEASYE 81

                         90
                 ....*....|....
gi 116062205 142 GSLIIVEADKKAAV 155
Cdd:COG0071   82 NGVLTITLPKAEEA 95

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 116062205  64 VDDLGDRLRILIDLPGMDRESLNIVVLEDRVEISARIREHVVKRalgslsekFSFREYRGVYRLPAPVDPRSVRIRTRGS 143
Cdd:cd00298    1 WYQTDDEVVVTVDLPGVKKEDIKVEVEDNVLTISGKREEEEERE--------RSYGEFERSFELPEDVDPEKSKASLENG 72

                 ....*...
gi 116062205 144 LIIVEADK 151
Cdd:cd00298   73 VLEITLPK 80

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 116062205  69 DRLRILIDLPGMDRESLNIVVLEDRVEISARIREHVVKRAlgslsekFSFREYRGVYRLPAPVDPRSV 136
Cdd:cd06478    7 DRFSVNLDVKHFSPEELSVKVLGDFVEIHGKHEERQDEHG-------FISREFHRRYRLPPGVDPAAI 67

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 116062205  64 VDDLGDRLRILIDLPGMDRESLNIVVLEDRVEISArirEHVVKRALGSlsekFSFREYRGVYRLPAPVDPRSV--RIRTR 141
Cdd:cd06526    2 VNDDDEKFQVTLDVKGFKPEELKVKVSDNKLVVEG---KHEEREDEHG----YVSREFTRRYQLPEGVDPDSVtsSLSSD 74

                         90
                 ....*....|
gi 116062205 142 GSLIIvEADK 151
Cdd:cd06526   75 GVLTI-EAPK 83