Biology:NDUFA3
 Generic protein structure example |
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 a 9.3 kDa protein composed of 84 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
- ↑ 1.0 1.1 1.2 1.3 1.4 "Entrez Gene: NDUFA1 NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 3, 9kDa". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=4694.
- ↑ 2.0 2.1 2.2 Voet, Donald; Voet, Judith G.; Pratt, Charlotte W. (2013). "18". Fundamentals of biochemistry: life at the molecular level (4th ed.). Hoboken, NJ: Wiley. pp. 581–620. ISBN 9780470547847.
- ↑ "Integration of cardiac proteome biology and medicine by a specialized knowledgebase". Circulation Research 113 (9): 1043–53. Oct 2013. doi:10.1161/CIRCRESAHA.113.301151. PMID 23965338.
- ↑ "NADH dehydrogenase [ubiquinone 1 alpha subcomplex subunit 1"]. Cardiac Organellar Protein Atlas Knowledgebase (COPaKB). https://amino.heartproteome.org/web/protein/O95167.
- ↑ "NDUFA3 - NADH dehydrogenase [ubiquinone 1 alpha subcomplex subunit 3"]. The UniProt Consortium. https://www.uniprot.org/uniprot/O95167. Retrieved 24 March 2015.
- ↑ "A proteome-wide, quantitative survey of in vivo ubiquitylation sites reveals widespread regulatory roles". Molecular & Cellular Proteomics 10 (10): M111.013284. Oct 2011. doi:10.1074/mcp.M111.013284. PMID 21890473.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
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