ID   PHCA_PORPU              Reviewed;         162 AA.
AC   P51378;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1996, sequence version 1.
DT   03-AUG-2022, entry version 76.
DE   RecName: Full=C-phycocyanin alpha chain;
GN   Name=cpcA;
OS   Porphyra purpurea (Red seaweed) (Ulva purpurea).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Bangiales; Bangiaceae; Porphyra.
OX   NCBI_TaxID=2787;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Avonport;
RA   Reith M.E., Munholland J.;
RT   "Complete nucleotide sequence of the Porphyra purpurea chloroplast
RT   genome.";
RL   Plant Mol. Biol. Rep. 13:333-335(1995).
CC   -!- FUNCTION: Light-harvesting photosynthetic bile pigment-protein from the
CC       phycobiliprotein complex (phycobilisome, PBS). Phycocyanin is the major
CC       phycobiliprotein in the PBS rod.
CC   -!- SUBUNIT: Heterodimer of an alpha and a beta subunit, which further
CC       assembles into trimers and the trimers into hexamers. The basic
CC       functional unit of phycobiliproteins is a ring-shaped hexamer formed
CC       from two back-to-back trimers contacting via the alpha chain subunits.
CC       The trimers are composed of alpha/beta subunit heterodimers arranged
CC       around a three-fold axis of symmetry. The phycoerythrins also contain a
CC       gamma subunit which is located in the center of the hexamer.
CC       {ECO:0000250|UniProtKB:P00306}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC       {ECO:0000250}; Peripheral membrane protein {ECO:0000250}; Stromal side
CC       {ECO:0000250}. Note=Part of the phycobilisome rod. {ECO:0000250}.
CC   -!- PTM: Contains one covalently linked phycocyanobilin chromophore.
CC       {ECO:0000250|UniProtKB:P00306}.
CC   -!- SIMILARITY: Belongs to the phycobiliprotein family. {ECO:0000305}.
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DR   EMBL; U38804; AAC08264.1; -; Genomic_DNA.
DR   PIR; S73299; S73299.
DR   RefSeq; NP_053988.1; NC_000925.1.
DR   AlphaFoldDB; P51378; -.
DR   SMR; P51378; -.
DR   GeneID; 810017; -.
DR   GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0030089; C:phycobilisome; IEA:UniProtKB-KW.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW.
DR   Gene3D; 1.10.490.20; -; 1.
DR   InterPro; IPR009050; Globin-like_sf.
DR   InterPro; IPR012128; Phycobilisome_asu/bsu.
DR   InterPro; IPR038719; Phycobilisome_asu/bsu_sf.
DR   InterPro; IPR006246; Phycocyanin_a.
DR   Pfam; PF00502; Phycobilisome; 1.
DR   PIRSF; PIRSF000081; Phycocyanin; 1.
DR   SUPFAM; SSF46458; SSF46458; 1.
DR   TIGRFAMs; TIGR01338; phycocy_alpha; 1.
PE   3: Inferred from homology;
KW   Antenna complex; Bile pigment; Chloroplast; Chromophore;
KW   Electron transport; Membrane; Photosynthesis; Phycobilisome; Plastid;
KW   Thylakoid; Transport.
FT   CHAIN           1..162
FT                   /note="C-phycocyanin alpha chain"
FT                   /id="PRO_0000199123"
FT   BINDING         84
FT                   /ligand="(2R,3E)-phycocyanobilin"
FT                   /ligand_id="ChEBI:CHEBI:85275"
FT                   /note="covalent, via 1 link"
FT                   /evidence="ECO:0000250|UniProtKB:P00306"
SQ   SEQUENCE   162 AA;  17450 MW;  FABCE9F07651A908 CRC64;
     MKTPITEAIA SADSQGRFLS NGELQAVNGR YQRAAASLGA ARSLTNNAQR LITGAAQSVY
     TKFPYVTQMP GPTYASSAIG KAKCARDIGY YLRMVTYCLV VGATGPMDEY LVAGLEEINR
     SFELSPSWYV EALQYIKGSH GLSGQIGNEA NVYLDYAINT LS