ID   PHEA3_CHRS2             Reviewed;         124 AA.
AC   U5TBU0;
DT   25-MAY-2022, integrated into UniProtKB/Swiss-Prot.
DT   22-JAN-2014, sequence version 1.
DT   03-AUG-2022, entry version 16.
DE   RecName: Full=Phycocyanin PC645 alpha-3 subunit {ECO:0000305};
OS   Chroomonas sp. (strain CCMP270).
OG   Plastid; Chloroplast {ECO:0000312|EMBL:AGY96988.1}.
OC   Eukaryota; Cryptophyceae; Pyrenomonadales; Chroomonadaceae; Chroomonas;
OC   unclassified Chroomonas.
OX   NCBI_TaxID=354589;
RN   [1] {ECO:0000312|EMBL:AGY96988.1}
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=24979784; DOI=10.1073/pnas.1402538111;
RA   Harrop S.J., Wilk K.E., Dinshaw R., Collini E., Mirkovic T., Teng C.Y.,
RA   Oblinsky D.G., Green B.R., Hoef-Emden K., Hiller R.G., Scholes G.D.,
RA   Curmi P.M.;
RT   "Single-residue insertion switches the quaternary structure and exciton
RT   states of cryptophyte light-harvesting proteins.";
RL   Proc. Natl. Acad. Sci. U.S.A. 111:E2666-E2675(2014).
CC   -!- FUNCTION: Light-harvesting photosynthetic tetrapyrrole chromophore-
CC       protein from the phycobiliprotein complex. {ECO:0000305}.
CC   -!- SUBUNIT: Heterotetramer of 2 different alpha chains and 2 identical
CC       beta chains which form 2 alpha-beta heterodimers within the
CC       heterotetramer. {ECO:0000250|UniProtKB:U5T880}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC       {ECO:0000305}; Peripheral membrane protein {ECO:0000305}; Lumenal side
CC       {ECO:0000305}.
CC   -!- PTM: Contains one phycocyanobilin chromophore and one mesobiliverdin
CC       chromophore with binding mediated by both the alpha and beta subunits.
CC       {ECO:0000250|UniProtKB:U5T880}.
CC   -!- MISCELLANEOUS: The light-harvesting system in Cryptophytes contains
CC       phycobiliprotein complexes. Unusually they are composed of either
CC       phycoerythrin (CPE) or phycocyanin (CPC) but never allophycocyanin
CC       (APC), with only one type of biliprotein being present in any one
CC       species. Unlike cyanobacteria or red algae these proteins are not
CC       arranged into higher-order phycobilisome complexes, and they are found
CC       in the thylakoid lumen. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the phycoerythrin family. {ECO:0000305}.
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DR   EMBL; KF314691; AGY96988.1; -; mRNA.
DR   GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0030089; C:phycobilisome; IEA:InterPro.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW.
DR   Gene3D; 3.90.510.10; -; 1.
DR   InterPro; IPR011070; Globular_prot_asu/bsu.
DR   InterPro; IPR037011; Phycoerythr-like_a_sf.
DR   InterPro; IPR004228; Phycoerythr_a.
DR   Pfam; PF02972; Phycoerythr_ab; 1.
DR   SUPFAM; SSF56568; SSF56568; 1.
PE   2: Evidence at transcript level;
KW   Bile pigment; Chloroplast; Chromophore; Electron transport; Membrane;
KW   Photosynthesis; Plastid; Thylakoid; Transport.
FT   CHAIN           1..124
FT                   /note="Phycocyanin PC645 alpha-3 subunit"
FT                   /id="PRO_5004664653"
FT   BINDING         71
FT                   /ligand="(2R,3E)-phycocyanobilin"
FT                   /ligand_id="ChEBI:CHEBI:85275"
FT                   /ligand_note="ligand shared with beta subunit"
FT                   /evidence="ECO:0000250|UniProtKB:U5T880"
FT   BINDING         73
FT                   /ligand="mesobiliverdin"
FT                   /ligand_id="ChEBI:CHEBI:189061"
FT                   /ligand_note="ligand shared with beta subunit"
FT                   /note="covalent"
FT                   /evidence="ECO:0000250|UniProtKB:U5T880"
FT   BINDING         81
FT                   /ligand="mesobiliverdin"
FT                   /ligand_id="ChEBI:CHEBI:189061"
FT                   /ligand_note="ligand shared with beta subunit"
FT                   /evidence="ECO:0000250|UniProtKB:U5T880"
FT   BINDING         97
FT                   /ligand="mesobiliverdin"
FT                   /ligand_id="ChEBI:CHEBI:189061"
FT                   /ligand_note="ligand shared with beta subunit"
FT                   /evidence="ECO:0000250|UniProtKB:U5T880"
SQ   SEQUENCE   124 AA;  13146 MW;  86080DC25482511E CRC64;
     MIAKTAVALA LVASAVALRP TMSLSANRRE VVAGAGAAAV VAPMLRPAEA NAVYTRGTSL
     SAPVITIFDA RGCTDHANKE YKGDWSGRAE DDECCVKIQM QKISVAEDVA RLVRLECLNE
     LKSK