ID   UCRIB_CYAPA             Reviewed;         241 AA.
AC   Q5CC92;
DT   05-JUL-2005, integrated into UniProtKB/Swiss-Prot.
DT   12-APR-2005, sequence version 1.
DT   03-AUG-2022, entry version 75.
DE   RecName: Full=Cytochrome b6-f complex iron-sulfur subunit 2, cyanelle;
DE            EC=7.1.1.6;
DE   AltName: Full=Plastohydroquinone:plastocyanin oxidoreductase iron-sulfur protein 2;
DE   AltName: Full=Rieske iron-sulfur protein 2;
DE            Short=ISP 2;
DE            Short=RISP 2;
DE   Flags: Precursor;
GN   Name=petC-2;
OS   Cyanophora paradoxa.
OC   Eukaryota; Glaucocystophyceae; Cyanophoraceae; Cyanophora.
OX   NCBI_TaxID=2762;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND PROTEIN IMPORT INTO ISOLATED CYANELLES.
RC   STRAIN=UTEX LB 555 / Pringsheim;
RX   PubMed=15691332; DOI=10.1111/j.1742-4658.2004.04533.x;
RA   Steiner J.M., Berghoefer J., Yusa F., Pompe J.A., Kloesgen R.B.,
RA   Loeffelhardt W.;
RT   "Conservative sorting in a primitive plastid. The cyanelle of Cyanophora
RT   paradoxa.";
RL   FEBS J. 272:987-998(2005).
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:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a plastoquinol + 2 H(+)(in) + 2 oxidized [plastocyanin] = a
CC         plastoquinone + 4 H(+)(out) + 2 reduced [plastocyanin];
CC         Xref=Rhea:RHEA:22148, Rhea:RHEA-COMP:9561, Rhea:RHEA-COMP:9562,
CC         Rhea:RHEA-COMP:10039, Rhea:RHEA-COMP:10040, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:17757, ChEBI:CHEBI:29036, ChEBI:CHEBI:49552,
CC         ChEBI:CHEBI:62192; EC=7.1.1.6;
CC   -!- COFACTOR:
CC       Name=[2Fe-2S] cluster; Xref=ChEBI:CHEBI:190135; Evidence={ECO:0000250};
CC       Note=Binds 1 [2Fe-2S] cluster per subunit. {ECO:0000250};
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, cyanelle thylakoid membrane
CC       {ECO:0000250}; Single-pass membrane protein {ECO:0000250}. Note=The
CC       transmembrane helix obliquely spans the membrane in one monomer, and
CC       its extrinsic C-terminal domain is part of the other monomer.
CC       {ECO:0000250}.
CC   -!- MISCELLANEOUS: This protein is 1 of 2 subunits of the cytochrome b6-f
CC       complex that are encoded in the nucleus.
CC   -!- MISCELLANEOUS: The Rieske iron-sulfur protein is a high potential 2Fe-
CC       2S protein.
CC   -!- SIMILARITY: Belongs to the Rieske iron-sulfur protein family.
CC       {ECO:0000255|HAMAP-Rule:MF_01335}.
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; AJ784853; CAH04961.1; -; mRNA.
DR   GO; GO:0033115; C:cyanelle thylakoid membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0051537; F:2 iron, 2 sulfur cluster binding; IEA:UniProtKB-KW.
DR   GO; GO:0045158; F:electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity; IEA:InterPro.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0009496; F:plastoquinol--plastocyanin reductase activity; IEA:UniProtKB-EC.
DR   Gene3D; 2.102.10.10; -; 1.
DR   HAMAP; MF_01335; Cytb6_f_Rieske; 1.
DR   InterPro; IPR023960; Cyt_b6_f_Rieske.
DR   InterPro; IPR017941; Rieske_2Fe-2S.
DR   InterPro; IPR036922; Rieske_2Fe-2S_sf.
DR   InterPro; IPR014349; Rieske_Fe-S_prot.
DR   InterPro; IPR005805; Rieske_Fe-S_prot_C.
DR   PANTHER; PTHR10134; PTHR10134; 1.
DR   Pfam; PF00355; Rieske; 1.
DR   PRINTS; PR00162; RIESKE.
DR   SUPFAM; SSF50022; SSF50022; 1.
DR   PROSITE; PS51296; RIESKE; 1.
PE   2: Evidence at transcript level;
KW   2Fe-2S; Cyanelle; Disulfide bond; Electron transport; Iron; Iron-sulfur;
KW   Membrane; Metal-binding; Plastid; Thylakoid; Transit peptide; Translocase;
KW   Transmembrane; Transmembrane helix; Transport.
FT   TRANSIT         1..62
FT                   /note="Cyanelle"
FT                   /evidence="ECO:0000255"
FT   CHAIN           63..241
FT                   /note="Cytochrome b6-f complex iron-sulfur subunit 2,
FT                   cyanelle"
FT                   /id="PRO_0000030688"
FT   TRANSMEM        83..103
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          127..223
FT                   /note="Rieske"
FT   BINDING         169
FT                   /ligand="[2Fe-2S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:190135"
FT                   /evidence="ECO:0000250"
FT   BINDING         171
FT                   /ligand="[2Fe-2S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:190135"
FT                   /evidence="ECO:0000250"
FT   BINDING         187
FT                   /ligand="[2Fe-2S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:190135"
FT                   /evidence="ECO:0000250"
FT   BINDING         190
FT                   /ligand="[2Fe-2S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:190135"
FT                   /evidence="ECO:0000250"
FT   DISULFID        174..189
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   241 AA;  24837 MW;  05D05D37A9DADACE CRC64;
     MSAFACSAVA APARGAIKAN SSSVCAIENG KAVAVGTSKQ VGAFKPVFAA AKAAKATTFS
     ISCSAASDEV PDMGKRKLMN LLLLGAIAGP TIGAGGPFVS FLVPPKSGGG AGAGQAAKDA
     AGNDIKVEKW LETXKPGDRS LAQGLKGDAT YLIVKEDGTL EKYGLNAVCT HLGCVVPWNQ
     SEGKFMCPCH GSQYDRTGKV VRGPAPLSLA LAHVNVLEDG VVAFEPWTET DFRTNTAPWW
     K