ID   PSBK_EUGGR              Reviewed;          54 AA.
AC   P31481;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1993, sequence version 1.
DT   25-MAY-2022, entry version 78.
DE   RecName: Full=Photosystem II reaction center protein K {ECO:0000255|HAMAP-Rule:MF_00441};
DE            Short=PSII-K {ECO:0000255|HAMAP-Rule:MF_00441};
DE   Flags: Precursor;
GN   Name=psbK {ECO:0000255|HAMAP-Rule:MF_00441};
OS   Euglena gracilis.
OG   Plastid; Chloroplast.
OC   Eukaryota; Discoba; Euglenozoa; Euglenida; Spirocuta; Euglenophyceae;
OC   Euglenales; Euglenaceae; Euglena.
OX   NCBI_TaxID=3039;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Z / UTEX 753;
RX   PubMed=8346031; DOI=10.1093/nar/21.15.3537;
RA   Hallick R.B., Hong L., Drager R.G., Favreau M.R., Monfort A., Orsat B.,
RA   Spielmann A., Stutz E.;
RT   "Complete sequence of Euglena gracilis chloroplast DNA.";
RL   Nucleic Acids Res. 21:3537-3544(1993).
CC   -!- FUNCTION: One of the components of the core complex of photosystem II
CC       (PSII). PSII is a light-driven water:plastoquinone oxidoreductase that
CC       uses light energy to abstract electrons from H(2)O, generating O(2) and
CC       a proton gradient subsequently used for ATP formation. It consists of a
CC       core antenna complex that captures photons, and an electron transfer
CC       chain that converts photonic excitation into a charge separation.
CC       {ECO:0000255|HAMAP-Rule:MF_00441}.
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_00441}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC       {ECO:0000255|HAMAP-Rule:MF_00441}; Single-pass membrane protein
CC       {ECO:0000255|HAMAP-Rule:MF_00441}.
CC   -!- SIMILARITY: Belongs to the PsbK family. {ECO:0000255|HAMAP-
CC       Rule:MF_00441}.
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DR   EMBL; Z11874; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   EMBL; X70810; CAA50085.1; -; Genomic_DNA.
DR   PIR; S34506; S34506.
DR   RefSeq; NP_041898.1; NC_001603.2.
DR   AlphaFoldDB; P31481; -.
DR   SMR; P31481; -.
DR   GeneID; 807484; -.
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_00441; PSII_PsbK; 1.
DR   InterPro; IPR003687; PSII_PsbK.
DR   InterPro; IPR037270; PSII_PsbK_sf.
DR   PANTHER; PTHR35325; PTHR35325; 1.
DR   Pfam; PF02533; PsbK; 1.
DR   SUPFAM; SSF161037; SSF161037; 1.
PE   3: Inferred from homology;
KW   Chloroplast; Membrane; Photosynthesis; Photosystem II; Plastid;
KW   Reaction center; Thylakoid; Transmembrane; Transmembrane helix.
FT   PROPEP          1..17
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00441"
FT                   /id="PRO_0000029459"
FT   CHAIN           18..54
FT                   /note="Photosystem II reaction center protein K"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00441"
FT                   /id="PRO_0000029460"
FT   TRANSMEM        29..49
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00441"
SQ   SEQUENCE   54 AA;  6314 MW;  68B688DC8561FC59 CRC64;
     MSFITLNNFF NTNTFFGLLP EQYAPFDPLI DVLPIIPVLF FLLAFVWQAS VKFR