AC MF_01379; DC Protein; auto TR HAMAP; MF_01379; -; 1; level=0 XX Names: PSII_PsbA_D1 XX ID PSBA DE RecName: Full=Photosystem II protein D1; DE Short=PSII D1 protein; DE EC=1.10.3.9; DE AltName: Full=Photosystem II Q(B) protein; case DE Flags: Precursor; end case GN Name=psbA; 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. 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. D1 provides most of CC the ligands for the Mn4-Ca-O5 cluster of the oxygen-evolving complex CC (OEC). There is also a Cl(-1) ion associated with D1 and D2, which is CC required for oxygen evolution. The PSII complex binds additional CC chlorophylls, carotenoids and 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 case CC -!- PTM: C-terminally processed by CtpA; processing is essential to allow CC assembly of the oxygen-evolving complex and thus photosynthetic growth. end case CC -!- PTM: #{Tyr-161} forms a radical intermediate that is referred to as CC redox-active TyrZ, YZ or Y-Z. CC -!- MISCELLANEOUS: 2 of the reaction center chlorophylls (ChlD1 and ChlD2) CC are entirely coordinated by water. CC -!- MISCELLANEOUS: Herbicides such as atrazine, BNT, diuron or ioxynil bind CC in the Q(B) binding site and block subsequent electron transfer. case CC -!- MISCELLANEOUS: Cyanobacteriota usually contain more than 2 copies of the CC psbA gene. end case 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; 0-3; trigger=no DR NCBIfam; TIGR01151; PsbA; 1; trigger=no XX case KW Phosphoprotein end case case KW Acetylation end case KW Calcium KW Chlorophyll KW Chromophore KW Electron transport KW Herbicide resistance KW Iron KW Manganese 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 GO GO:0016682; F:oxidoreductase activity, acting on diphenols and related substances as donors, oxygen as acceptor 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: PSBA_THEVL (P51765) FT TRANSMEM 29..46 FT /note="Helical" FT TRANSMEM 118..133 FT /note="Helical" FT TRANSMEM 142..156 FT /note="Helical" FT TRANSMEM 197..218 FT /note="Helical" FT TRANSMEM 274..288 FT /note="Helical" FT SITE 344..345 FT /note="Cleavage; by CtpA" FT Tag: Cleavage; Optional; Condition: A-[ACDGSTV] case and FT INIT_MET 1 FT /note="Removed" FT Condition: M FT MOD_RES 2 FT /note="N-acetylthreonine" FT Tag: acetyl; Condition: T FT MOD_RES 2 FT /note="Phosphothreonine" FT Tag: phospho; Condition: T FT CHAIN 2..344 FT /note="Photosystem II protein D1" FT PROPEP 345..Cter else case and not FT CHAIN Nter..344 FT /note="Photosystem II protein D1" FT PROPEP 345..Cter else FT CHAIN Nter..Cter FT /note="Photosystem II protein D1" end case FT BINDING 118 FT /ligand="chlorophyll a" FT /ligand_id="ChEBI:CHEBI:58416" FT /ligand_label="ChlzD1" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: H FT BINDING 170 FT /ligand="[CaMn4O5] cluster" FT /ligand_id="ChEBI:CHEBI:189552" FT Condition: [DE] FT BINDING 189 FT /ligand="[CaMn4O5] cluster" FT /ligand_id="ChEBI:CHEBI:189552" FT Condition: [ED] FT BINDING 198 FT /ligand="chlorophyll a" FT /ligand_id="ChEBI:CHEBI:58416" FT /ligand_label="PD1" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: H FT BINDING 215 FT /ligand="Fe cation" FT /ligand_id="ChEBI:CHEBI:24875" FT /ligand_note="ligand shared with heterodimeric FT partner" FT Condition: H FT BINDING 272 FT /ligand="Fe cation" FT /ligand_id="ChEBI:CHEBI:24875" FT /ligand_note="ligand shared with heterodimeric FT partner" FT Condition: H FT BINDING 332 FT /ligand="[CaMn4O5] cluster" FT /ligand_id="ChEBI:CHEBI:189552" FT Condition: H FT BINDING 333 FT /ligand="[CaMn4O5] cluster" FT /ligand_id="ChEBI:CHEBI:189552" FT Condition: E FT BINDING 342 FT /ligand="[CaMn4O5] cluster" FT /ligand_id="ChEBI:CHEBI:189552" FT Condition: D FT BINDING 344 FT /ligand="[CaMn4O5] cluster" FT /ligand_id="ChEBI:CHEBI:189552" FT Condition: A FT BINDING 126 FT /ligand="pheophytin a" FT /ligand_id="ChEBI:CHEBI:136840" FT /ligand_label="D1" FT Condition: [YW] FT BINDING 215 FT /ligand="a quinone" FT /ligand_id="ChEBI:CHEBI:132124" FT /ligand_label="B" FT Condition: H FT BINDING 264..265 FT /ligand="a quinone" FT /ligand_id="ChEBI:CHEBI:132124" FT /ligand_label="B" FT Condition: [AS]-F FT SITE 161 FT /note="Tyrosine radical intermediate" FT Condition: Y FT SITE 190 FT /note="Stabilizes free radical intermediate" FT Condition: H XX Size: 340-363; Related: None; Template: P51765; P0A444; P69560; P07753; P16033; Scope: Bacteria; Cyanobacteriota Plastid Fusion: Nter: None Cter: None Duplicate: in Cyanobacteriota Plasmid: None Comments: C-terminal cleavage of D1 by the C-terminal processing protese (CtpA) within the thylakoid lumen is required for ligation of the manganese cluster and association of the oxygen-evolving complex. EUGGR, BIGNA, LEPTE, STAPU and many dinoflagellates are already this length and thus do not seem to be encoded as precursor proteins. One copy in TRIV2 (Q3M5L6) does not have the cleavage site. D1 is very photosensitive and there is a mechanism to replace photodamaged D1. XX # Revision 1.46 2023/06/20 //