ID   PSBI_PROMM              Reviewed;          39 AA.
AC   Q7V4U9;
DT   21-AUG-2007, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2003, sequence version 1.
DT   25-MAY-2022, entry version 89.
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 4.4 kDa protein {ECO:0000255|HAMAP-Rule:MF_01316};
GN   Name=psbI {ECO:0000255|HAMAP-Rule:MF_01316}; OrderedLocusNames=PMT_1840;
OS   Prochlorococcus marinus (strain MIT 9313).
OC   Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC   Prochlorococcus.
OX   NCBI_TaxID=74547;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=MIT 9313;
RX   PubMed=12917642; DOI=10.1038/nature01947;
RA   Rocap G., Larimer F.W., Lamerdin J.E., Malfatti S., Chain P., Ahlgren N.A.,
RA   Arellano A., Coleman M., Hauser L., Hess W.R., Johnson Z.I., Land M.L.,
RA   Lindell D., Post A.F., Regala W., Shah M., Shaw S.L., Steglich C.,
RA   Sullivan M.B., Ting C.S., Tolonen A., Webb E.A., Zinser E.R.,
RA   Chisholm S.W.;
RT   "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche
RT   differentiation.";
RL   Nature 424:1042-1047(2003).
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: Cyanobacterial PSII is composed of 1 copy each of membrane
CC       proteins PsbA, PsbB, PsbC, PsbD, PsbE, PsbF, PsbH, PsbI, PsbJ, PsbK,
CC       PsbL, PsbM, PsbT, PsbX, PsbY, PsbZ, Ycf12, at least 3 peripheral
CC       proteins PsbO, PsbU, PsbV and a large number of cofactors. It forms
CC       dimeric complexes. {ECO:0000255|HAMAP-Rule:MF_01316}.
CC   -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC       Rule:MF_01316}; Single-pass membrane protein {ECO:0000255|HAMAP-
CC       Rule:MF_01316}.
CC   -!- SIMILARITY: Belongs to the PsbI family. {ECO:0000255|HAMAP-
CC       Rule:MF_01316}.
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DR   EMBL; BX548175; CAE22015.1; -; Genomic_DNA.
DR   RefSeq; WP_011131207.1; NC_005071.1.
DR   AlphaFoldDB; Q7V4U9; -.
DR   SMR; Q7V4U9; -.
DR   STRING; 74547.PMT_1840; -.
DR   EnsemblBacteria; CAE22015; CAE22015; PMT_1840.
DR   KEGG; pmt:PMT_1840; -.
DR   HOGENOM; CLU_212150_0_0_3; -.
DR   Proteomes; UP000001423; Chromosome.
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:0031676; C:plasma membrane-derived thylakoid membrane; IEA:UniProtKB-SubCell.
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   Pfam; PF02532; PsbI; 1.
DR   SUPFAM; SSF161041; SSF161041; 1.
PE   3: Inferred from homology;
KW   Membrane; Photosynthesis; Photosystem II; Reaction center;
KW   Reference proteome; Thylakoid; Transmembrane; Transmembrane helix.
FT   CHAIN           1..39
FT                   /note="Photosystem II reaction center protein I"
FT                   /id="PRO_0000298298"
FT   TRANSMEM        6..26
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01316"
SQ   SEQUENCE   39 AA;  4398 MW;  42099A585A349E5D CRC64;
     MLALKLSVYS VVFFFIAVFV FGFLASDPSR TPARKDLED