ID   PSBI_CROS5              Reviewed;          38 AA.
AC   B1WYX8;
DT   04-NOV-2008, integrated into UniProtKB/Swiss-Prot.
DT   04-NOV-2008, sequence version 2.
DT   25-MAY-2022, entry version 65.
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=cce_3394;
OS   Crocosphaera subtropica (strain ATCC 51142 / BH68) (Cyanothece sp. (strain
OS   ATCC 51142)).
OC   Bacteria; Cyanobacteria; Oscillatoriophycideae; Chroococcales;
OC   Aphanothecaceae; Crocosphaera; Crocosphaera subtropica.
OX   NCBI_TaxID=43989;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51142 / BH68;
RX   PubMed=18812508; DOI=10.1073/pnas.0805418105;
RA   Welsh E.A., Liberton M., Stoeckel J., Loh T., Elvitigala T., Wang C.,
RA   Wollam A., Fulton R.S., Clifton S.W., Jacobs J.M., Aurora R., Ghosh B.K.,
RA   Sherman L.A., Smith R.D., Wilson R.K., Pakrasi H.B.;
RT   "The genome of Cyanothece 51142, a unicellular diazotrophic cyanobacterium
RT   important in the marine nitrogen cycle.";
RL   Proc. Natl. Acad. Sci. U.S.A. 105:15094-15099(2008).
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}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=ACB52742.1; Type=Erroneous initiation; Note=Extended N-terminus.; Evidence={ECO:0000305};
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DR   EMBL; CP000806; ACB52742.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; WP_008276509.1; NC_010546.1.
DR   AlphaFoldDB; B1WYX8; -.
DR   SMR; B1WYX8; -.
DR   STRING; 43989.cce_3394; -.
DR   EnsemblBacteria; ACB52742; ACB52742; cce_3394.
DR   KEGG; cyt:cce_3394; -.
DR   eggNOG; ENOG5033CII; Bacteria.
DR   HOGENOM; CLU_212150_0_0_3; -.
DR   OrthoDB; 2079393at2; -.
DR   Proteomes; UP000001203; Chromosome circular.
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   PANTHER; PTHR35772; PTHR35772; 1.
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..38
FT                   /note="Photosystem II reaction center protein I"
FT                   /id="PRO_0000353214"
FT   TRANSMEM        6..26
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01316"
SQ   SEQUENCE   38 AA;  4340 MW;  DB0C034089338CD0 CRC64;
     MLTLKIAVYI VVAFFISLFV FGFLSSDPTR NPGRKDFE