NDUFA3

NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 3, 9kDa
Identifiers
Aliases NDUFA3, B9, CI-B9
External IDs MGI: 1913341 HomoloGene: 3338 GeneCards: 4696
Orthologs
Species Human Mouse
Entrez

4696

66091

Ensembl

ENSG00000276220

ENSMUSG00000035674

UniProt

O95167

Q9CQ91

RefSeq (mRNA)

NM_004542

NM_025348

RefSeq (protein)

NP_004533.1

NP_079624.1

Location (UCSC) Chr 19: 54.1 – 54.11 Mb Chr 7: 3.62 – 3.62 Mb
PubMed search
Wikidata
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NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 3 is a protein that in humans is encoded by the NDUFA3 gene.[1] The NDUFA3 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.[2]

Structure

The NDUFA3 gene is located on the q arm of chromosome 19 at position 13.42, and it has a total span of 4,123 base pairs.[1] The NDUFA3 gene produces an 11 kDa protein composed of 99 amino acids.[3][4] NDUFA3 is a subunit of the enzyme NADH dehydrogenase (ubiquinone), the largest of the respiratory complexes. The structure is L-shaped with a long, hydrophobic transmembrane domain and a hydrophilic domain for the peripheral arm that includes all the known redox centers and the NADH binding site.[2] NDUFA3 is one of about 31 hydrophobic subunits that form the transmembrane region of Complex I. It has been noted that the N-terminal hydrophobic domain has the potential to be folded into an alpha helix spanning the inner mitochondrial membrane with a C-terminal hydrophilic domain interacting with globular subunits of Complex I. The highly conserved two-domain structure suggests that this feature is critical for the protein function and that the hydrophobic domain acts as an anchor for the NADH:ubiquinone oxidoreductase complex at the inner mitochondrial membrane.[1]

Function

The human NDUFA3 gene codes for a subunit of Complex I of the respiratory chain, which transfers electrons from NADH to ubiquinone.[1] However, NDUFA3 is an accessory subunit of the complex that is believed not to be involved in catalysis.[5] Initially, NADH binds to Complex I and transfers two electrons to the isoalloxazine ring of the flavin mononucleotide (FMN) prosthetic arm to form FMNH2. The electrons are transferred through a series of iron-sulfur (Fe-S) clusters in the prosthetic arm and finally to coenzyme Q10 (CoQ), which is reduced to ubiquinol (CoQH2). The flow of electrons changes the redox state of the protein, resulting in a conformational change and pK shift of the ionizable side chain, which pumps four hydrogen ions out of the mitochondrial matrix.[2]

Interactions

NDUFA3 has been shown to interact with ubiquitin C, a polyubiquitin precursor.[1][6]

References

  1. 1 2 3 4 5 "Entrez Gene: NDUFA1 NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 3, 9kDa".
  2. 1 2 3 Voet D, Voet JG, Pratt CW (2013). "18". Fundamentals of biochemistry: life at the molecular level (4th ed.). Hoboken, NJ: Wiley. pp. 581–620. ISBN 9780470547847.
  3. ↑ Zong NC, Li H, Li H, Lam MP, Jimenez RC, Kim CS, Deng N, Kim AK, Choi JH, Zelaya I, Liem D, Meyer D, Odeberg J, Fang C, Lu HJ, Xu T, Weiss J, Duan H, Uhlen M, Yates JR, Apweiler R, Ge J, Hermjakob H, Ping P (Oct 2013). "Integration of cardiac proteome biology and medicine by a specialized knowledgebase". Circulation Research 113 (9): 1043–53. doi:10.1161/CIRCRESAHA.113.301151. PMC 4076475. PMID 23965338.
  4. ↑ "NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 1". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB).
  5. ↑ "NDUFA3 - NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 3". UniProt: a hub for protein information. The UniProt Consortium. Retrieved 24 March 2015.
  6. ↑ Wagner SA, Beli P, Weinert BT, Nielsen ML, Cox J, Mann M, Choudhary C (Oct 2011). "A proteome-wide, quantitative survey of in vivo ubiquitylation sites reveals widespread regulatory roles". Molecular & Cellular Proteomics 10 (10): M111.013284. doi:10.1074/mcp.M111.013284. PMC 3205876. PMID 21890473.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

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