ID   PETD_OLTVI              Reviewed;         160 AA.
AC   Q20ET6;
DT   31-OCT-2006, integrated into UniProtKB/Swiss-Prot.
DT   18-APR-2006, sequence version 1.
DT   25-MAY-2022, entry version 59.
DE   RecName: Full=Cytochrome b6-f complex subunit 4 {ECO:0000255|HAMAP-Rule:MF_01344};
DE   AltName: Full=17 kDa polypeptide {ECO:0000255|HAMAP-Rule:MF_01344};
GN   Name=petD {ECO:0000255|HAMAP-Rule:MF_01344};
OS   Oltmannsiellopsis viridis (Marine flagellate) (Oltmannsiella viridis).
OG   Plastid; Chloroplast.
OC   Eukaryota; Viridiplantae; Chlorophyta; Ulvophyceae; Oltmannsiellopsidales;
OC   Oltmannsiellopsidaceae; Oltmannsiellopsis.
OX   NCBI_TaxID=51324;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=16472375; DOI=10.1186/1741-7007-4-3;
RA   Pombert J.-F., Lemieux C., Turmel M.;
RT   "The complete chloroplast DNA sequence of the green alga Oltmannsiellopsis
RT   viridis reveals a distinctive quadripartite architecture in the chloroplast
RT   genome of early diverging ulvophytes.";
RL   BMC Biol. 4:3-3(2006).
CC   -!- FUNCTION: Component of the cytochrome b6-f complex, which mediates
CC       electron transfer between photosystem II (PSII) and photosystem I
CC       (PSI), cyclic electron flow around PSI, and state transitions.
CC       {ECO:0000255|HAMAP-Rule:MF_01344}.
CC   -!- SUBUNIT: The 4 large subunits of the cytochrome b6-f complex are
CC       cytochrome b6, subunit IV (17 kDa polypeptide, petD), cytochrome f and
CC       the Rieske protein, while the 4 small subunits are petG, petL, petM and
CC       petN. The complex functions as a dimer (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC       {ECO:0000255|HAMAP-Rule:MF_01344}; Multi-pass membrane protein
CC       {ECO:0000255|HAMAP-Rule:MF_01344}.
CC   -!- SIMILARITY: Belongs to the cytochrome b family. PetD subfamily.
CC       {ECO:0000255|HAMAP-Rule:MF_01344}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; DQ291132; ABB81977.1; -; Genomic_DNA.
DR   EMBL; DQ291132; ABB82014.1; -; Genomic_DNA.
DR   RefSeq; YP_635853.1; NC_008099.1.
DR   RefSeq; YP_635909.1; NC_008099.1.
DR   AlphaFoldDB; Q20ET6; -.
DR   SMR; Q20ET6; -.
DR   GeneID; 4100073; -.
DR   GeneID; 4100117; -.
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:0045158; F:electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0045156; F:electron transporter, transferring electrons within the cyclic electron transport pathway of photosynthesis activity; IEA:InterPro.
DR   GO; GO:0009767; P:photosynthetic electron transport chain; IEA:InterPro.
DR   CDD; cd00290; cytochrome_b_C; 1.
DR   HAMAP; MF_01344; Cytb6_f_subIV; 1.
DR   InterPro; IPR005798; Cyt_b/b6_C.
DR   InterPro; IPR036150; Cyt_b/b6_C_sf.
DR   InterPro; IPR005870; Cyt_b6/f_cplx_suIV.
DR   Pfam; PF00032; Cytochrom_B_C; 1.
DR   PIRSF; PIRSF000033; B6f_17K; 1.
DR   SUPFAM; SSF81648; SSF81648; 1.
DR   TIGRFAMs; TIGR01156; cytb6/f_IV; 1.
DR   PROSITE; PS51003; CYTB_CTER; 1.
PE   3: Inferred from homology;
KW   Chloroplast; Electron transport; Membrane; Photosynthesis; Plastid;
KW   Thylakoid; Transmembrane; Transmembrane helix; Transport.
FT   CHAIN           1..160
FT                   /note="Cytochrome b6-f complex subunit 4"
FT                   /id="PRO_0000255568"
FT   TRANSMEM        36..56
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01344"
FT   TRANSMEM        95..115
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01344"
FT   TRANSMEM        131..151
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01344"
SQ   SEQUENCE   160 AA;  17374 MW;  4EC83EEC81B5A096 CRC64;
     MAVTKKPDLS DPVLRAKLAK GMGHNYYGEP AWPNDLLYMF PVVILGTFAL SISLAVLAPA
     AMGEPANPFA TPLEILPEWY FYPVFQILRV VPNKLLGVLC MAAVPVGLIT VPFIESINKF
     QNPFRRPIAS TLFLFGTATA VWLGIGAALP IDISLTLGLF