ID   PHCA_PORPP              Reviewed;         162 AA.
AC   P37207;
DT   01-OCT-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1994, sequence version 1.
DT   03-AUG-2022, entry version 85.
DE   RecName: Full=R-phycocyanin-1 subunit alpha;
DE   AltName: Full=R-phycocyanin I alpha chain;
GN   Name=rpcA; Synonyms=cpcA;
OS   Porphyridium purpureum (Red alga) (Porphyridium cruentum).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Porphyridiales; Porphyridiaceae;
OC   Porphyridium.
OX   NCBI_TaxID=35688;
RN   [1]
RP   PROTEIN SEQUENCE, SUBUNIT, SUBCELLULAR LOCATION, AND CHROMOPHORE.
RC   STRAIN=1380-1A;
RX   PubMed=8168545; DOI=10.1111/j.1432-1033.1994.tb18769.x;
RA   Ducret A., Sidler W., Frank G., Zuber H.;
RT   "The complete amino acid sequence of R-phycocyanin-I alpha and beta
RT   subunits from the red alga Porphyridium cruentum. Structural and
RT   phylogenetic relationships of the phycocyanins within the phycobiliprotein
RT   families.";
RL   Eur. J. Biochem. 221:563-580(1994).
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 (PubMed:8168545).
CC       Dimers further assemble into trimers and the trimers into hexamers. The
CC       basic functional unit of phycobiliproteins is a ring-shaped hexamer
CC       formed from two back-to-back trimers contacting via the alpha chain
CC       subunits. The trimers are composed of alpha/beta subunit heterodimers
CC       arranged around a three-fold axis of symmetry. The phycoerythrins also
CC       contain a gamma subunit which is located in the center of the hexamer
CC       (By similarity). {ECO:0000250|UniProtKB:P00306,
CC       ECO:0000269|PubMed:8168545}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane;
CC       Peripheral membrane protein; Stromal side. Note=Part of the
CC       phycobilisome rod. {ECO:0000269|PubMed:8168545}.
CC   -!- PTM: Contains one covalently linked phycocyanobilin chromophore.
CC       {ECO:0000269|PubMed:8168545}.
CC   -!- SIMILARITY: Belongs to the phycobiliprotein family. {ECO:0000305}.
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DR   PIR; S43238; S43238.
DR   AlphaFoldDB; P37207; -.
DR   SMR; P37207; -.
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   1: Evidence at protein level;
KW   Antenna complex; Bile pigment; Chloroplast; Chromophore;
KW   Direct protein sequencing; Electron transport; Membrane; Photosynthesis;
KW   Phycobilisome; Plastid; Thylakoid; Transport.
FT   CHAIN           1..162
FT                   /note="R-phycocyanin-1 subunit alpha"
FT                   /id="PRO_0000199136"
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:P59858,
FT                   ECO:0000305|PubMed:8168545"
SQ   SEQUENCE   162 AA;  17463 MW;  DE5D4B580AE8D44C CRC64;
     MKTPITEAIA TADNQGRFLS NTELQAVNGR YQRATASLTA AKALTGSAQR LITGAAQAVY
     NKFPYTTQMP GPAYASSAIG KAKCARDIGY YLRMVTYTLV VGGTGPMDEY LVAGLEEINR
     SFDLSPSWYI EALQYIKNSH GLSGQVANEA NAYIDYAINT SL