ID   CRYAA_TUPTE             Reviewed;         173 AA.
AC   P02506;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   03-AUG-2022, entry version 90.
DE   RecName: Full=Alpha-crystallin A chain;
GN   Name=CRYAA;
OS   Tupinambis teguixin (Golden tegu).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Laterata;
OC   Teiioidea; Teiidae; Tupinambis.
OX   NCBI_TaxID=8532;
RN   [1]
RP   AMINO-ACID COMPOSITION OF PEPTIDES, PARTIAL PROTEIN SEQUENCE, AND
RP   ACETYLATION AT MET-1.
RX   PubMed=3870872; DOI=10.1093/oxfordjournals.molbev.a040367;
RA   de Jong W.W., Zweers A., Versteeg M., Dessauer H.C., Goodman M.;
RT   "Alpha-crystallin A sequences of Alligator mississippiensis and the lizard
RT   Tupinambis teguixin: molecular evolution and reptilian phylogeny.";
RL   Mol. Biol. Evol. 2:484-493(1985).
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-100 and Glu-102 from one molecule are
CC       ligands of the zinc ion, and His-107 and His-154 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   PIR; B25753; CYLZAA.
DR   AlphaFoldDB; P02506; -.
DR   SMR; P02506; -.
DR   iPTMnet; P02506; -.
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   1: Evidence at protein level;
KW   Acetylation; Cytoplasm; Direct protein sequencing; Eye lens protein;
KW   Glycoprotein; Metal-binding; Nucleus; Zinc.
FT   CHAIN           1..173
FT                   /note="Alpha-crystallin A chain"
FT                   /id="PRO_0000125899"
FT   DOMAIN          52..162
FT                   /note="sHSP"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00285"
FT   REGION          144..173
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   BINDING         100
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   BINDING         102
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   BINDING         107
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   BINDING         154
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_label="3"
FT                   /evidence="ECO:0000250|UniProtKB:P02470"
FT   MOD_RES         1
FT                   /note="N-acetylmethionine"
FT                   /evidence="ECO:0000269|PubMed:3870872"
FT   CARBOHYD        162
FT                   /note="O-linked (GlcNAc) serine"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   173 AA;  19898 MW;  3097BBDDB261AAE3 CRC64;
     MDITIQHPWF KRALGPLIPS RLFDQFFGEG LFEYDLLPLF SSTISPYYRQ SLFRTVLESG
     ISEVRSDRDK FTIFLDVKHF SPEDLSVKVI EDFVEIHGKH NERQDDHGYI SREFHRRYRL
     PSNVDQAAIT CSLSADGMLT FAAPKVQSNT DPSHNERPIP VSREEKPTSA PPS