CY1_EUGGR
ID CY1_EUGGR Reviewed; 243 AA.
AC P20114;
DT 01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1991, sequence version 1.
DT 03-AUG-2022, entry version 110.
DE RecName: Full=Cytochrome c1, heme protein;
DE EC=7.1.1.8;
DE AltName: Full=Complex III subunit 4;
DE AltName: Full=Complex III subunit IV;
DE AltName: Full=Cytochrome b-c1 complex subunit 4;
DE AltName: Full=Ubiquinol-cytochrome-c reductase complex cytochrome c1 subunit;
DE Short=Cytochrome c-1;
OS Euglena gracilis.
OC Eukaryota; Discoba; Euglenozoa; Euglenida; Spirocuta; Euglenophyceae;
OC Euglenales; Euglenaceae; Euglena.
OX NCBI_TaxID=3039;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], AND PARTIAL PROTEIN SEQUENCE.
RC STRAIN=SM-ZK;
RX PubMed=2558110; DOI=10.1093/oxfordjournals.jbchem.a122877;
RA Mukai K., Wakabayashi S., Matsubara H.;
RT "Molecular cloning and nucleotide sequence of a cDNA encoding Euglena
RT gracilis cytochrome c1.";
RL J. Biochem. 106:479-482(1989).
RN [2]
RP HEME-BINDING PEPTIDE.
RX PubMed=2536325; DOI=10.1111/j.1432-1033.1989.tb14494.x;
RA Mukai K., Toyosaki H., Yoshida M., Yao Y., Wakabayashi S., Matsubara H.;
RT "An atypical heme-binding structure of cytochrome c1 of Euglena gracilis
RT mitochondrial complex III.";
RL Eur. J. Biochem. 178:649-656(1989).
CC -!- FUNCTION: Component of the ubiquinol-cytochrome c oxidoreductase, a
CC multisubunit transmembrane complex that is part of the mitochondrial
CC electron transport chain which drives oxidative phosphorylation. The
CC respiratory chain contains 3 multisubunit complexes succinate
CC dehydrogenase (complex II, CII), ubiquinol-cytochrome c oxidoreductase
CC (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase
CC (complex IV, CIV), that cooperate to transfer electrons derived from
CC NADH and succinate to molecular oxygen, creating an electrochemical
CC gradient over the inner membrane that drives transmembrane transport
CC and the ATP synthase. The cytochrome b-c1 complex catalyzes electron
CC transfer from ubiquinol to cytochrome c, linking this redox reaction to
CC translocation of protons across the mitochondrial inner membrane, with
CC protons being carried across the membrane as hydrogens on the quinol.
CC In the process called Q cycle, 2 protons are consumed from the matrix,
CC 4 protons are released into the intermembrane space and 2 electrons are
CC passed to cytochrome c. Cytochrome c1 is a catalytic core subunit
CC containing a c-type heme. It transfers electrons from the [2Fe-2S]
CC iron-sulfur cluster of the Rieske protein to cytochrome c.
CC {ECO:0000250|UniProtKB:P07143}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a quinol + 2 Fe(III)-[cytochrome c](out) = a quinone + 2
CC Fe(II)-[cytochrome c](out) + 2 H(+)(out); Xref=Rhea:RHEA:11484,
CC Rhea:RHEA-COMP:10350, Rhea:RHEA-COMP:14399, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:24646, ChEBI:CHEBI:29033, ChEBI:CHEBI:29034,
CC ChEBI:CHEBI:132124; EC=7.1.1.8;
CC Evidence={ECO:0000250|UniProtKB:P07143};
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000250|UniProtKB:P07143};
CC Note=Binds 1 heme group covalently per subunit.
CC {ECO:0000250|UniProtKB:P07143};
CC -!- SUBUNIT: Component of the ubiquinol-cytochrome c oxidoreductase
CC (cytochrome b-c1 complex, complex III, CIII), a multisubunit enzyme
CC composed of 3 respiratory subunits cytochrome b, cytochrome c1 and
CC Rieske protein, 2 core protein subunits, and additional low-molecular
CC weight protein subunits. The complex exists as an obligatory dimer and
CC forms supercomplexes (SCs) in the inner mitochondrial membrane with
CC cytochrome c oxidase (complex IV, CIV). {ECO:0000250|UniProtKB:P07143}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P07143}; Single-pass membrane protein
CC {ECO:0000250|UniProtKB:P07143}.
CC -!- MISCELLANEOUS: This cytochrome c1 is unusual, its alpha-band exists at
CC 561 nm instead at 553 nm.
CC -!- SIMILARITY: Belongs to the cytochrome c family. {ECO:0000305}.
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 PIR; JQ0021; JQ0021.
DR AlphaFoldDB; P20114; -.
DR SMR; P20114; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0070469; C:respirasome; IEA:UniProtKB-KW.
DR GO; GO:0020037; F:heme binding; IEA:InterPro.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008121; F:ubiquinol-cytochrome-c reductase activity; IEA:UniProtKB-EC.
DR Gene3D; 1.10.760.10; -; 1.
DR InterPro; IPR036909; Cyt_c-like_dom_sf.
DR InterPro; IPR002326; Cyt_c1.
DR InterPro; IPR021157; Cyt_c1_TM_anchor_C.
DR PANTHER; PTHR10266; PTHR10266; 1.
DR Pfam; PF02167; Cytochrom_C1; 1.
DR PRINTS; PR00603; CYTOCHROMEC1.
DR SUPFAM; SSF46626; SSF46626; 1.
DR SUPFAM; SSF81496; SSF81496; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Electron transport; Heme; Iron; Membrane;
KW Metal-binding; Mitochondrion; Mitochondrion inner membrane;
KW Respiratory chain; Translocase; Transmembrane; Transmembrane helix;
KW Transport.
FT CHAIN 1..243
FT /note="Cytochrome c1, heme protein"
FT /id="PRO_0000108417"
FT TOPO_DOM 1..201
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000250|UniProtKB:P07143"
FT TRANSMEM 202..221
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 222..243
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P07143"
FT DOMAIN 5..194
FT /note="Cytochrome c"
FT BINDING 39
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /note="covalent"
FT /evidence="ECO:0000269|PubMed:2558110"
FT BINDING 40
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P07143"
FT BINDING 159
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P07143"
SQ SEQUENCE 243 AA; 27855 MW; 922A2B8D5440C75A CRC64;
GVDSHPPALP WPHFQWFQGL DWRSVRRGKE VYEQVFAPCH SLSFIKYRHF EAFMSKEEVK
NMAASFEVDD DPDEKGEARK RPGKRFDTVV QPYKNEQEAR YANNGALPPD LSVITNARHG
GVDYIYALLT GYGRPVPGGV QLSTTQWYNP YFHGGIIGMP PPLTDDMIEY EDGTPASVPQ
MAKDVTCFLE WCSNPWWDER KLLGYKTIAT LAVIAVSSGY YNRFLSGLWR SRRLAFRPFN
YSK
