AC MF_01383; DC Protein; auto TR HAMAP; MF_01383; -; 1; level=0 XX Names: PSII_PsbD_D2 XX ID PSBD DE RecName: Full=Photosystem II D2 protein; DE Short=PSII D2 protein; DE EC=1.10.3.9; DE AltName: Full=Photosystem Q(A) protein; GN Name=psbD; XX CC -!- FUNCTION: Photosystem II (PSII) is a light-driven water:plastoquinone CC oxidoreductase that uses light energy to abstract electrons from H(2)O, CC generating O(2) and a proton gradient subsequently used for ATP CC formation. It consists of a core antenna complex that captures photons, CC and an electron transfer chain that converts photonic excitation into a CC charge separation. The D1/D2 (PsbA/PsbD) reaction center heterodimer CC binds P680, the primary electron donor of PSII as well as several CC subsequent electron acceptors. D2 is needed for assembly of a stable CC PSII complex. CC -!- CATALYTIC ACTIVITY: CC Reaction=2 a plastoquinone + 2 H2O + 4 hnu = 2 a plastoquinol + O2; CC Xref=Rhea:RHEA:36359, Rhea:RHEA-COMP:9561, Rhea:RHEA-COMP:9562, CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15379, ChEBI:CHEBI:17757, CC ChEBI:CHEBI:30212, ChEBI:CHEBI:62192; EC=1.10.3.9; CC -!- COFACTOR: CC Note=The D1/D2 heterodimer binds P680, chlorophylls that are the CC primary electron donor of PSII, and subsequent electron acceptors. It CC shares a non-heme iron and each subunit binds pheophytin, quinone, CC additional chlorophylls, carotenoids and lipids. There is also a Cl(-1) CC ion associated with D1 and D2, which is required for oxygen evolution. CC The PSII complex binds additional chlorophylls, carotenoids and CC specific lipids.; case 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, Psb30/Ycf12, peripheral proteins PsbO, CyanoQ (PsbQ), CC PsbU, PsbV and a large number of cofactors. It forms dimeric complexes. else 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, Psb30/Ycf12, at least 3 peripheral proteins of the CC oxygen-evolving complex and a large number of cofactors. It forms CC dimeric complexes. end case case CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane; Multi- CC pass membrane protein. else case CC -!- SUBCELLULAR LOCATION: Cell inner membrane; Multi-pass membrane protein. else CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane; Multi-pass membrane CC protein. end case CC -!- MISCELLANEOUS: 2 of the reaction center chlorophylls (ChlD1 and ChlD2) CC are entirely coordinated by water. CC -!- SIMILARITY: Belongs to the reaction center PufL/M/PsbA/D family. XX DR PROSITE; PS00244; REACTION_CENTER; 1; trigger=no DR Pfam; PF00124; Photo_RC; 1; trigger=no DR PRINTS; PR00256; REACTNCENTRE; 1; trigger=no DR NCBIfam; TIGR01152; PsbD; 1; trigger=no XX KW Chlorophyll KW Chromophore KW Electron transport KW Iron KW Magnesium KW Membrane KW Metal-binding KW Oxidoreductase KW Photosynthesis KW Photosystem II case KW Cell membrane KW Cell inner membrane else KW Thylakoid end case KW Transmembrane KW Transport KW Transmembrane helix XX GO GO:0016168; F:chlorophyll binding GO GO:0009055; F:electron transfer activity GO GO:0005506; F:iron ion binding GO GO:0015979; P:photosynthesis case GO GO:0009535; C:chloroplast thylakoid membrane else case GO GO:0005886; C:plasma membrane else GO GO:0042651; C:thylakoid membrane end case XX FT From: PSBD_THEVL (D0VWR8) FT TRANSMEM 30..50 FT /note="Helical" FT TRANSMEM 114..130 FT /note="Helical" FT TRANSMEM 142..155 FT /note="Helical" FT TRANSMEM 197..217 FT /note="Helical" FT TRANSMEM 268..284 FT /note="Helical" FT BINDING 107 FT /ligand="chlorophyll a" FT /ligand_id="ChEBI:CHEBI:58416" FT /ligand_label="ChlzD2" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: H FT BINDING 187 FT /ligand="chlorophyll a" FT /ligand_id="ChEBI:CHEBI:58416" FT /ligand_label="PD2" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: H FT BINDING 204 FT /ligand="Fe cation" FT /ligand_id="ChEBI:CHEBI:24875" FT /ligand_note="ligand shared with heterodimeric FT partner" FT Condition: H FT BINDING 258 FT /ligand="Fe cation" FT /ligand_id="ChEBI:CHEBI:24875" FT /ligand_note="ligand shared with heterodimeric FT partner" FT Condition: H FT BINDING 119 FT /ligand="pheophytin a" FT /ligand_id="ChEBI:CHEBI:136840" FT /ligand_label="D2" FT Condition: Q FT BINDING 132 FT /ligand="pheophytin a" FT /ligand_id="ChEBI:CHEBI:136840" FT /ligand_label="D2" FT Condition: N FT BINDING 204 FT /ligand="a plastoquinone" FT /ligand_id="ChEBI:CHEBI:17757" FT /ligand_label="Q(A)" FT Condition: H FT BINDING 251 FT /ligand="a plastoquinone" FT /ligand_id="ChEBI:CHEBI:17757" FT /ligand_label="Q(A)" FT Condition: F XX Size: 350-365; Related: None; Template: D0VWR8; Q8CM25; P56761; P06005; Scope: Bacteria; Cyanobacteriota Plastid Fusion: Nter: None Cter: None Duplicate: None Plasmid: None Comments: D2 is phosphorylated in "higer" and "lower eukaryotes" (Ceratodon purpureus, Marchantia polymorpha, Adiantum tenerum, in the last 3 the site was not identified) but not in red algae or cyanobacteria (Ceramium tenuicorne and Synechocystis, see PubMed:9512353). Cyanobacteriota often have more than 1 (often identical) gene for this protein. XX # Revision 1.27 2023/06/20 //