ID   NU3M_PORPU              Reviewed;         121 AA.
AC   O99978;
DT   30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1999, sequence version 1.
DT   25-MAY-2022, entry version 62.
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   Porphyra purpurea (Red seaweed) (Ulva purpurea).
OG   Mitochondrion.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Bangiales; Bangiaceae; Porphyra.
OX   NCBI_TaxID=2787;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Burger G., Saint-Louis D., Gray M.W., Lang B.F.;
RT   "Complete sequence of the mitochondrial DNA of the red alga, Porphyra
RT   purpurea. Inverted repeats, sequence polymorphisms, and cyanobacterial
RT   introns.";
RL   Submitted (DEC-1998) to the EMBL/GenBank/DDBJ databases.
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; AF114794; AAD03105.1; -; Genomic_DNA.
DR   PIR; T11226; T11226.
DR   RefSeq; NP_049302.1; NC_002007.1.
DR   AlphaFoldDB; O99978; -.
DR   SMR; O99978; -.
DR   GeneID; 809774; -.
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..121
FT                   /note="NADH-ubiquinone oxidoreductase chain 3"
FT                   /id="PRO_0000117814"
FT   TRANSMEM        11..31
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        63..83
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        90..110
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   121 AA;  14073 MW;  E84A53D0714DE836 CRC64;
     MNVLYNEYSA ILTFFAISFS ISTLILALSY FLNPQPSDQE KVSAYECGFN PFDDARATFD
     VRFYLVAILF LIFDLEISFL FPWSLVLGQL SIFGFWSMIV FLIILTLGFI YEWKKGALEW
     E