ID   NU2M_SQUAC              Reviewed;         348 AA.
AC   Q9ZZ53;
DT   30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1999, sequence version 1.
DT   25-MAY-2022, entry version 81.
DE   RecName: Full=NADH-ubiquinone oxidoreductase chain 2;
DE            EC=7.1.1.2;
DE   AltName: Full=NADH dehydrogenase subunit 2;
GN   Name=MT-ND2; Synonyms=MTND2, NADH2, ND2;
OS   Squalus acanthias (Spiny dogfish).
OG   Mitochondrion.
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Chondrichthyes;
OC   Elasmobranchii; Squalomorphii; Squaliformes; Squalidae; Squalus.
OX   NCBI_TaxID=7797;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=9873084; DOI=10.1007/pl00006439;
RA   Rasmussen A.S., Arnason U.;
RT   "Phylogenetic studies of complete mitochondrial DNA molecules place
RT   cartilaginous fishes within the tree of bony fishes.";
RL   J. Mol. Evol. 48:118-123(1999).
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 inner membrane; Multi-pass membrane
CC       protein.
CC   -!- SIMILARITY: Belongs to the complex I subunit 2 family. {ECO:0000305}.
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DR   EMBL; Y18134; CAA77050.1; -; Genomic_DNA.
DR   PIR; T11535; T11535.
DR   RefSeq; NP_008524.1; NC_002012.1.
DR   AlphaFoldDB; Q9ZZ53; -.
DR   SMR; Q9ZZ53; -.
DR   GeneID; 808386; -.
DR   CTD; 4536; -.
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:0008137; F:NADH dehydrogenase (ubiquinone) activity; IEA:UniProtKB-EC.
DR   GO; GO:0006120; P:mitochondrial electron transport, NADH to ubiquinone; IEA:InterPro.
DR   InterPro; IPR010933; NADH_DH_su2_C.
DR   InterPro; IPR003917; NADH_UbQ_OxRdtase_chain2.
DR   InterPro; IPR001750; ND/Mrp_mem.
DR   Pfam; PF06444; NADH_dehy_S2_C; 1.
DR   Pfam; PF00361; Proton_antipo_M; 1.
DR   PRINTS; PR01436; NADHDHGNASE2.
PE   3: Inferred from homology;
KW   Electron transport; Membrane; Mitochondrion; Mitochondrion inner membrane;
KW   NAD; Respiratory chain; Translocase; Transmembrane; Transmembrane helix;
KW   Transport; Ubiquinone.
FT   CHAIN           1..348
FT                   /note="NADH-ubiquinone oxidoreductase chain 2"
FT                   /id="PRO_0000117639"
FT   TRANSMEM        3..23
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        25..45
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        67..87
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        95..115
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        118..138
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        149..171
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        178..198
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        203..223
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        240..260
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        274..294
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        324..344
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   348 AA;  38341 MW;  D6DD349BC63F1B35 CRC64;
     MNPVVLTIII SSLGLGTMMT FIGSHWLLVW MGLEINTLAI IPLMIRQHHP RAVEATTKYF
     LTQATASALL LFASITNAWS LGEWSLLEML NPTSATLVTI ALALKIGLAP MHFWLPEVLQ
     GLDLITGLIL ATWQKLAPFA ILLQLHPMLN SNLLLFLGVS STVIGGWGGL NQTQLRKILA
     YSSIAHLGWM ITILHYSPNL TQLNLALYII MTLTTFLLFK LFNSTKINSI AISTIKSPLL
     SIIALITLLS LGGLPPLSGF MPKWLILQEL TKQDLAIPAT IMALAALLSL FFYLRLCYST
     TLTMSPNSIY LSSSWRTKSL QPNLILMMAT SLSILLLPLT PTIFMLTL