CRYAB_SQUAC
ID CRYAB_SQUAC Reviewed; 177 AA.
AC P02512;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 1.
DT 03-AUG-2022, entry version 83.
DE RecName: Full=Alpha-crystallin B chain;
DE AltName: Full=Alpha(B)-crystallin;
GN Name=CRYAB;
OS Squalus acanthias (Spiny dogfish).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Chondrichthyes;
OC Elasmobranchii; Squalomorphii; Squaliformes; Squalidae; Squalus.
OX NCBI_TaxID=7797;
RN [1]
RP PROTEIN SEQUENCE, AND ACETYLATION AT MET-1.
RX PubMed=3356684; DOI=10.1016/s0021-9258(18)60691-x;
RA de Jong W.W., Leunissen J.A.M., Leenen P.J.M., Zweers A., Versteeg M.;
RT "Dogfish alpha-crystallin sequences. Comparison with small heat shock
RT proteins and Schistosoma egg antigen.";
RL J. Biol. Chem. 263:5141-5149(1988).
CC -!- FUNCTION: May contribute to the transparency and refractive index of
CC the lens.
CC -!- SUBUNIT: Heteromer composed of three CRYAA and one CRYAB subunits.
CC Aggregates with homologous proteins, including the small heat shock
CC protein HSPB1, to form large heteromeric complexes. Inter-subunit
CC bridging via zinc ions enhances stability, which is crucial as there is
CC no protein turn over in the lens. Interacts with HSPBAP1 and TTN/titin
CC (By similarity). {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the small heat shock protein (HSP20) family.
CC {ECO:0000255|PROSITE-ProRule:PRU00285}.
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DR PIR; B28190; CYDFAB.
DR AlphaFoldDB; P02512; -.
DR SMR; P02512; -.
DR iPTMnet; P02512; -.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0042803; F:protein homodimerization activity; ISS:UniProtKB.
DR GO; GO:0005212; F:structural constituent of eye lens; IEA:UniProtKB-KW.
DR Gene3D; 2.60.40.790; -; 1.
DR InterPro; IPR002068; A-crystallin/Hsp20_dom.
DR InterPro; IPR001436; Alpha-crystallin/sHSP_animal.
DR InterPro; IPR003090; Alpha-crystallin_N.
DR InterPro; IPR008978; HSP20-like_chaperone.
DR PANTHER; PTHR45640; PTHR45640; 1.
DR Pfam; PF00525; Crystallin; 1.
DR Pfam; PF00011; HSP20; 1.
DR PIRSF; PIRSF036514; Sm_HSP_B1; 1.
DR PRINTS; PR00299; ACRYSTALLIN.
DR SUPFAM; SSF49764; SSF49764; 1.
DR PROSITE; PS01031; SHSP; 1.
PE 1: Evidence at protein level;
KW Acetylation; Direct protein sequencing; Eye lens protein; Metal-binding;
KW Zinc.
FT CHAIN 1..177
FT /note="Alpha-crystallin B chain"
FT /id="PRO_0000125921"
FT DOMAIN 58..166
FT /note="sHSP"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00285"
FT REGION 155..177
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 85
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 106
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 108
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 113
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 121
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT MOD_RES 1
FT /note="N-acetylmethionine"
FT /evidence="ECO:0000269|PubMed:3356684"
SQ SEQUENCE 177 AA; 20254 MW; 3C1FBEBD23D78D5C CRC64;
MDIAIQHPWL RRPLFPSSIF PSRIFDQNFG EHFDPDLFPS FSSMLSPFYW RMGAPMARMP
SWAQTGLSEL RLDKDKFAIH LDVKHFTPEE LRVKILGDFI EVQAQHEERQ DEHGYVSREF
HRKYKVPAGV DPLVITCSLS ADGVLTITGP RKVADVPERS VPISRDEKPA VAGPQQK
