ID   CRYAA_ANAPL             Reviewed;         149 AA.
AC   O12984;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1997, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Alpha-crystallin A chain;
DE   Flags: Fragment;
GN   Name=CRYAA;
OS   Anas platyrhynchos (Mallard) (Anas boschas).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda;
OC   Coelurosauria; Aves; Neognathae; Galloanserae; Anseriformes; Anatidae;
OC   Anatinae; Anas.
OX   NCBI_TaxID=8839;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=Pekin breed; TISSUE=Lens;
RX   PubMed=9126559; DOI=10.1006/mpev.1996.0384;
RA   Caspers G.J., Uit de Weerd D., Wattel J., de Jong W.W.;
RT   "Alpha-crystallin sequences support a galliform/anseriform clade.";
RL   Mol. Phylogenet. Evol. 7:185-188(1997).
CC   -!- FUNCTION: Contributes to the transparency and refractive index of the
CC       lens. May act as a chaperone, preventing aggregation of various
CC       proteins under a wide range of stress conditions.
CC       {ECO:0000250|UniProtKB:P02489}.
CC   -!- SUBUNIT: Heteropolymer composed of three CRYAA and one CRYAB subunits
CC       (By similarity). Inter-subunit bridging via zinc ions enhances
CC       stability, which is crucial as there is no protein turn over in the
CC       lens. Can also form homodimers and homotetramers (dimers of dimers)
CC       which serve as the building blocks of homooligomers (By similarity).
CC       Within homooligomers, the zinc-binding motif is created from residues
CC       of 3 different molecules. His-89 and Glu-91 from one molecule are
CC       ligands of the zinc ion, and His-96 and His-143 residues from
CC       additional molecules complete the site with tetrahedral coordination
CC       geometry (By similarity). {ECO:0000250|UniProtKB:P02470,
CC       ECO:0000250|UniProtKB:P02489}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P02489}. Nucleus
CC       {ECO:0000250|UniProtKB:P02489}. Note=Translocates to the nucleus during
CC       heat shock. {ECO:0000250|UniProtKB:P02489}.
CC   -!- SIMILARITY: Belongs to the small heat shock protein (HSP20) family.
CC       {ECO:0000255|PROSITE-ProRule:PRU00285}.
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DR   EMBL; X96592; CAA65410.1; -; mRNA.
DR   AlphaFoldDB; O12984; -.
DR   SMR; O12984; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
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; IPR012274; Alpha-crystallin_A.
DR   InterPro; IPR003090; Alpha-crystallin_N.
DR   InterPro; IPR008978; HSP20-like_chaperone.
DR   PANTHER; PTHR45640; PTHR45640; 1.
DR   PANTHER; PTHR45640:SF14; PTHR45640:SF14; 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   2: Evidence at transcript level;
KW   Cytoplasm; Eye lens protein; Metal-binding; Nucleus; Zinc.
FT   CHAIN           <1..>149
FT                   /note="Alpha-crystallin A chain"
FT                   /id="PRO_0000125892"
FT   DOMAIN          41..149
FT                   /note="sHSP"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00285"
FT   BINDING         89
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   BINDING         91
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   BINDING         96
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   BINDING         143
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="3"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   NON_TER         1
FT   NON_TER         149
SQ   SEQUENCE   149 AA;  17017 MW;  35815475430B7290 CRC64;
     RALGPLIPSR LFDQFFGEGL LEYDLLPLFS STISPYYRQS LFRSVLESGI SEVRSDRDKF
     TIMLDVKHFS PEDLSVKIID DFVEIHGKHS ERQDDHGYIS REFHRRYRLP ANVDQSAITC
     SLSGDGMLTF SGPKVPSNMD PTHSERPIP