ID   PSBI_CYACA              Reviewed;          38 AA.
AC   O19882;
DT   15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 71.
DE   RecName: Full=Photosystem II reaction center protein I {ECO:0000255|HAMAP-Rule:MF_01316};
DE            Short=PSII-I {ECO:0000255|HAMAP-Rule:MF_01316};
DE   AltName: Full=PSII 4.8 kDa protein {ECO:0000255|HAMAP-Rule:MF_01316};
GN   Name=psbI {ECO:0000255|HAMAP-Rule:MF_01316};
OS   Cyanidium caldarium (Red alga).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Cyanidiales; Cyanidiaceae; Cyanidium.
OX   NCBI_TaxID=2771;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=RK-1;
RX   PubMed=11040290; DOI=10.1007/s002390010101;
RA   Gloeckner G., Rosenthal A., Valentin K.-U.;
RT   "The structure and gene repertoire of an ancient red algal plastid
RT   genome.";
RL   J. Mol. Evol. 51:382-390(2000).
CC   -!- FUNCTION: One of the components of the core complex of photosystem II
CC       (PSII), required for its stability and/or assembly. PSII is a light-
CC       driven water:plastoquinone oxidoreductase that uses light energy to
CC       abstract electrons from H(2)O, generating O(2) and a proton gradient
CC       subsequently used for ATP formation. It consists of a core antenna
CC       complex that captures photons, and an electron transfer chain that
CC       converts photonic excitation into a charge separation.
CC       {ECO:0000255|HAMAP-Rule:MF_01316}.
CC   -!- SUBUNIT: PSII is composed of 1 copy each of membrane proteins PsbA,
CC       PsbB, PsbC, PsbD, PsbE, PsbF, PsbH, PsbI, PsbJ, PsbK, PsbL, PsbM, PsbT,
CC       PsbX, PsbY, PsbZ, Ycf12, at least 3 peripheral proteins of the oxygen-
CC       evolving complex and a large number of cofactors. It forms dimeric
CC       complexes. {ECO:0000255|HAMAP-Rule:MF_01316}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC       {ECO:0000255|HAMAP-Rule:MF_01316}; Single-pass membrane protein
CC       {ECO:0000255|HAMAP-Rule:MF_01316}.
CC   -!- SIMILARITY: Belongs to the PsbI family. {ECO:0000255|HAMAP-
CC       Rule:MF_01316}.
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DR   EMBL; AF022186; AAB82707.1; -; Genomic_DNA.
DR   PIR; T11950; T11950.
DR   RefSeq; NP_045054.1; NC_001840.1.
DR   PDB; 4YUU; X-ray; 2.77 A; I1/I2/i1/i2=1-38.
DR   PDBsum; 4YUU; -.
DR   AlphaFoldDB; O19882; -.
DR   SMR; O19882; -.
DR   PRIDE; O19882; -.
DR   GeneID; 800258; -.
DR   GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0009539; C:photosystem II reaction center; IEA:InterPro.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR   HAMAP; MF_01316; PSII_PsbI; 1.
DR   InterPro; IPR003686; PSII_PsbI.
DR   InterPro; IPR037271; PSII_PsbI_sf.
DR   PANTHER; PTHR35772; PTHR35772; 1.
DR   Pfam; PF02532; PsbI; 1.
DR   SUPFAM; SSF161041; SSF161041; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Chloroplast; Membrane; Photosynthesis; Photosystem II;
KW   Plastid; Reaction center; Thylakoid; Transmembrane; Transmembrane helix.
FT   CHAIN           1..38
FT                   /note="Photosystem II reaction center protein I"
FT                   /id="PRO_0000219623"
FT   TRANSMEM        4..24
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01316"
SQ   SEQUENCE   38 AA;  4468 MW;  C0413E3807FCEB5A CRC64;
     MFTLKIFVYS CVAFFCSLFI FGFLSNDPSR NPNRKDLE