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respiratory chain complex I

Definition

Target type: cellularcomponent

Respiratory chain complex I is an enzyme of the respiratory chain. It consists of several polypeptide chains and is L-shaped, with a horizontal arm lying in the membrane and a vertical arm that projects into the matrix. The electrons of NADH enter the chain at this complex. [GOC:imk, GOC:jid, ISBN:0716749556]

Respiratory chain complex I, also known as NADH dehydrogenase or Complex I, is a large multi-subunit enzyme located in the inner mitochondrial membrane. It is the first enzyme in the electron transport chain, which is responsible for generating ATP, the primary energy currency of the cell. Complex I is a complex and dynamic structure, consisting of 45 distinct protein subunits in mammals. These subunits can be grouped into three functional domains: the NADH dehydrogenase module, which binds NADH and initiates electron transfer; the transmembrane domain, which contains the electron transfer chain and proton translocation pathways; and the matrix arm, which interacts with other components of the electron transport chain and facilitates the movement of electrons. The NADH dehydrogenase module is composed of seven subunits (N-module) that form a large, L-shaped structure with a hydrophilic domain containing the NADH binding site and a hydrophobic domain that interacts with the transmembrane domain. The transmembrane domain is comprised of 14 subunits (Q-module) that form a transmembrane channel, where electrons are transferred from NADH to ubiquinone (Q), a mobile electron carrier in the mitochondrial membrane. The matrix arm contains 24 subunits (P-module) and is embedded in the mitochondrial matrix. It interacts with the other respiratory chain complexes and facilitates the transfer of electrons and protons between the complexes. The intricate structure and complex interplay of these domains enable complex I to perform its essential role in cellular respiration. It catalyzes the transfer of electrons from NADH to ubiquinone, coupled with the translocation of protons from the mitochondrial matrix to the intermembrane space. This proton gradient drives the synthesis of ATP via oxidative phosphorylation, providing the cell with the energy it needs to function.'
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Proteins (3)

ProteinDefinitionTaxonomy
Acyl carrier protein, mitochondrialAn acyl carrier protein, mitochondrial that is encoded in the genome of cow. [OMA:P52505, PRO:DNx]Bos taurus (cattle)
NADH dehydrogenase [ubiquinone] flavoprotein 1, mitochondrialAn NADH dehydrogenase [ubiquinone] flavoprotein 1, mitochondrial that is encoded in the genome of cow. [OMA:P25708, PRO:DNx]Bos taurus (cattle)
NADH-ubiquinone oxidoreductase chain 1[no definition available]Bos taurus (cattle)

Compounds (7)

CompoundDefinitionClassesRoles
rotenoneDerris: A plant genus of the family FABACEAE. The root is a source of rotenoids (ROTENONE) and flavonoids. Some species of Pongamia have been reclassified to this genus and some to MILLETTIA. Some species of Deguelia have been reclassified to this genus.

rotenoid : Members of the class of tetrahydrochromenochromene that consists of a cis-fused tetrahydrochromeno[3,4-b]chromene skeleton and its substituted derivatives. The term was originally restricted to natural products, but is now also used to describe semi-synthetic and fully synthetic compounds.
organic heteropentacyclic compound;
rotenones
antineoplastic agent;
metabolite;
mitochondrial NADH:ubiquinone reductase inhibitor;
phytogenic insecticide;
piscicide;
toxin
desacetyluvaricindesacetyluvaricin: isolated from Uvaria accuminata; structure given in first source
squamocinsquamocin: from seeds of Annona squamosa; a trihydroxy-bis-tetrahydrofuran fatty acid lactone; inhibits E. coli NADH:quinone oxidoreductase (NDH-1); structure given in first sourcepolyketide
capsaicinALGRX-4975: an injectable capsaicin (TRPV1 receptor agonist) formulation for longlasting pain relief

capsaicinoid : A family of aromatic fatty amides produced as secondary metabolites by chilli peppers.
capsaicinoidnon-narcotic analgesic;
TRPV1 agonist;
voltage-gated sodium channel blocker
piericidin apiericidin A : A member of the class of monohydroxypyridines that acts as an irreversible mitochondrial Complex I inhibitor that strongly associates with ubiquinone binding sites in both mitochondrial and bacterial forms of NADH:ubiquinone oxidoreductase

piericidin A: pyridine-substituted fatty alcohol antibiotic; minor descriptor (75-85); on-line & Index Medicus search ANTIBIOTICS (75-85); RN given refers to (S-(R*,R*-(all-E)))-isomer
aromatic ether;
methylpyridines;
monohydroxypyridine;
secondary allylic alcohol
antimicrobial agent;
bacterial metabolite;
EC 1.6.5.3 [NADH:ubiquinone reductase (H(+)-translocating)] inhibitor;
mitochondrial respiratory-chain inhibitor
fenpyroximatefenpyroximate: structure in first sourcepyrazole acaricide;
tert-butyl ester
mitochondrial NADH:ubiquinone reductase inhibitor
laherradurinlaherradurin: structure in first source