ID   NU3M_RECAM              Reviewed;         122 AA.
AC   O21273;
DT   30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 69.
DE   RecName: Full=NADH-ubiquinone oxidoreductase chain 3;
DE            EC=7.1.1.2;
DE   AltName: Full=NADH dehydrogenase subunit 3;
GN   Name=NAD3;
OS   Reclinomonas americana.
OG   Mitochondrion.
OC   Eukaryota; Discoba; Jakobida; Histionina; Histionidae; Reclinomonas.
OX   NCBI_TaxID=48483;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 50394;
RX   PubMed=9168110; DOI=10.1038/387493a0;
RA   Lang B.F., Burger G., O'Kelly C.J., Cedergren R., Golding G.B., Lemieux C.,
RA   Sankoff D., Turmel M., Gray M.W.;
RT   "An ancestral mitochondrial DNA resembling a eubacterial genome in
RT   miniature.";
RL   Nature 387:493-497(1997).
CC   -!- FUNCTION: Core subunit of the mitochondrial membrane respiratory chain
CC       NADH dehydrogenase (Complex I) that is believed to belong to the
CC       minimal assembly required for catalysis. Complex I functions in the
CC       transfer of electrons from NADH to the respiratory chain. The immediate
CC       electron acceptor for the enzyme is believed to be ubiquinone (By
CC       similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a ubiquinone + 5 H(+)(in) + NADH = a ubiquinol + 4 H(+)(out) +
CC         NAD(+); Xref=Rhea:RHEA:29091, Rhea:RHEA-COMP:9565, Rhea:RHEA-
CC         COMP:9566, ChEBI:CHEBI:15378, ChEBI:CHEBI:16389, ChEBI:CHEBI:17976,
CC         ChEBI:CHEBI:57540, ChEBI:CHEBI:57945; EC=7.1.1.2;
CC   -!- SUBCELLULAR LOCATION: Mitochondrion membrane {ECO:0000250}; Multi-pass
CC       membrane protein {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the complex I subunit 3 family. {ECO:0000305}.
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DR   EMBL; AF007261; AAD11900.1; -; Genomic_DNA.
DR   PIR; S78167; S78167.
DR   RefSeq; NP_044785.1; NC_001823.1.
DR   AlphaFoldDB; O21273; -.
DR   SMR; O21273; -.
DR   GeneID; 801095; -.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0031966; C:mitochondrial membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0070469; C:respirasome; IEA:UniProtKB-KW.
DR   GO; GO:0008137; F:NADH dehydrogenase (ubiquinone) activity; IEA:UniProtKB-EC.
DR   Gene3D; 1.20.58.1610; -; 1.
DR   HAMAP; MF_01394; NDH1_NuoA; 1.
DR   InterPro; IPR023043; NAD(P)H_OxRDtase_bac/plastid.
DR   InterPro; IPR000440; NADH_UbQ/plastoQ_OxRdtase_su3.
DR   InterPro; IPR038430; NDAH_ubi_oxred_su3_sf.
DR   PANTHER; PTHR11058; PTHR11058; 1.
DR   Pfam; PF00507; Oxidored_q4; 1.
PE   3: Inferred from homology;
KW   Electron transport; Membrane; Mitochondrion; NAD; Respiratory chain;
KW   Translocase; Transmembrane; Transmembrane helix; Transport; Ubiquinone.
FT   CHAIN           1..122
FT                   /note="NADH-ubiquinone oxidoreductase chain 3"
FT                   /id="PRO_0000117819"
FT   TRANSMEM        12..32
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        66..86
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        91..111
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   122 AA;  14050 MW;  0E08E35DF170A897 CRC64;
     MNTMILSEYL SVLIFFIFSF GLSCIILGLS YVLATQNADT EKLSPYECGF NPFDDARGAF
     DVRFYLVAIL FIIFDLEVAF LFPWAVALSD VTIFGFWTMF IFLLILTVGF IYEWKKGALD
     WE