NDUFA7

NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 7, 14.5kDa
Identifiers
Symbols NDUFA7 ; B14.5a
External IDs OMIM: 602139 HomoloGene: 37994 GeneCards: NDUFA7 Gene
Orthologs
Species Human Mouse
Entrez 4701 66416
Ensembl ENSG00000267855 ENSMUSG00000041881
UniProt O95182 Q9Z1P6
RefSeq (mRNA) NM_005001 NM_023202
RefSeq (protein) NP_004992 NP_075691
Location (UCSC) Chr 19:
8.31 – 8.32 Mb		 Chr 17:
33.82 – 33.84 Mb
PubMed search

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 7 is an enzyme that in humans is encoded by the NDUFA7 gene.[1] The NDUFA7 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 NDUFA7 gene is located on the p arm of chromosome 19 in position 13.2 and spans 12,618 base pairs.[1] The gene produces a 12.5 kDa protein composed of 113 amino acids.[3][4] NDUFA7 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] 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 dehydrogenase (ubiquinone) complex at the inner mitochondrial membrane. NDUFA7 is one of about 31 hydrophobic subunits that form the transmembrane region of Complex I. The predicted secondary structure is primarily alpha helix, but the carboxy-terminal half of the protein has high potential to adopt a coiled-coil form. The amino-terminal part contains a putative beta sheet rich in hydrophobic amino acids that may serve as mitochondrial import signal. Related pseudogenes have also been identified on four other chromosomes.[1][5][6][7]

Function

The human NDUFA7 gene codes for a subunit of Complex I of the respiratory chain, which transfers electrons from NADH to ubiquinone.[1] 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]

References

  1. 1 2 3 4 "Entrez Gene: NDUFA7 NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 7".
  2. 1 2 3 Pratt, Donald Voet, Judith G. Voet, Charlotte W. (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. ↑ "NDUFA7 - NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 7". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB).
  5. ↑ Emahazion T, Beskow A, Gyllensten U, Brookes AJ (Nov 1998). "Intron based radiation hybrid mapping of 15 complex I genes of the human electron transport chain". Cytogenet Cell Genet 82 (1-2): 115–9. doi:10.1159/000015082. PMID 9763677.
  6. ↑ Emahazion T, Brookes AJ (Nov 1998). "Mapping of the NDUFA2, NDUFA6, NDUFA7, NDUFB8, and NDUFS8 electron transport chain genes by intron based radiation hybrid mapping". Cytogenet Cell Genet 82 (1–2): 114. doi:10.1159/000015081. PMID 9763676.
  7. ↑ Ton C, Hwang DM, Dempsey AA, Liew CC (Jan 1998). "Identification and primary structure of five human NADH-ubiquinone oxidoreductase subunits". Biochem Biophys Res Commun 241 (2): 589–94. doi:10.1006/bbrc.1997.7707. PMID 9425316.

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

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