ID   PETD_TRIV2              Reviewed;         160 AA.
AC   Q9L3Q0; Q3M7I7;
DT   24-JAN-2006, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2000, sequence version 1.
DT   25-MAY-2022, entry version 115.
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}; OrderedLocusNames=Ava_3442;
OS   Trichormus variabilis (strain ATCC 29413 / PCC 7937) (Anabaena variabilis).
OC   Bacteria; Cyanobacteria; Nostocales; Nostocaceae; Trichormus.
OX   NCBI_TaxID=240292;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=FD;
RA   Arnold M.;
RT   "b6f complex of Anabaena variabilis.";
RL   Submitted (OCT-2000) to the EMBL/GenBank/DDBJ databases.
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 29413 / PCC 7937;
RX   PubMed=25197444; DOI=10.4056/sigs.3899418;
RA   Thiel T., Pratte B.S., Zhong J., Goodwin L., Copeland A., Lucas S., Han C.,
RA   Pitluck S., Land M.L., Kyrpides N.C., Woyke T.;
RT   "Complete genome sequence of Anabaena variabilis ATCC 29413.";
RL   Stand. Genomic Sci. 9:562-573(2014).
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. {ECO:0000255|HAMAP-
CC       Rule:MF_01344}.
CC   -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC       Rule:MF_01344}; Multi-pass membrane protein {ECO:0000255|HAMAP-
CC       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; AJ271818; CAB72243.1; -; Genomic_DNA.
DR   EMBL; CP000117; ABA23049.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q9L3Q0; -.
DR   SMR; Q9L3Q0; -.
DR   STRING; 240292.Ava_3442; -.
DR   EnsemblBacteria; ABA23049; ABA23049; Ava_3442.
DR   KEGG; ava:Ava_3442; -.
DR   eggNOG; COG1290; Bacteria.
DR   HOGENOM; CLU_112652_0_0_3; -.
DR   OMA; KKGMGHN; -.
DR   Proteomes; UP000002533; Chromosome.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0031676; C:plasma membrane-derived thylakoid membrane; IEA:UniProtKB-SubCell.
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   Electron transport; Membrane; Photosynthesis; Thylakoid; Transmembrane;
KW   Transmembrane helix; Transport.
FT   CHAIN           1..160
FT                   /note="Cytochrome b6-f complex subunit 4"
FT                   /id="PRO_0000061899"
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;  17527 MW;  635DF825728FA303 CRC64;
     MATQKKPDLS DPTLRAKLAK GMGHNYYGEP AWPNDLLYVF PIVIMGSFAC IVALAVLDPA
     MTGEPANPFA TPLEILPEWY LYPVFQILRS LPNKLLGVLA MASVPLGLIL VPFIENVNKF
     QNPFRRPVAT TVFLFGTLVT LWLGIGAALP LDKSLTLGLF