This is an old revision of this page, as edited by ProteinBoxBot(talk | contribs) at 05:42, 15 April 2016(Updating to new gene infobox populated via wikidata). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 05:42, 15 April 2016 by ProteinBoxBot(talk | contribs)(Updating to new gene infobox populated via wikidata)
The NDUFB6 gene is located on the p arm of chromosome 9 in position 21.1 and is 19,659 base pairs long.[9][10]
Structure
The NDUFB6 protein weighs 17 kDa and is composed of 128 amino acids.[9][10] NDUFB6 is a subunit of the enzyme NADH dehydrogenase (ubiquinone), the largest of the respiratory complexes. The structure is L-shaped with a long, hydrophobictransmembrane domain and a hydrophilic domain for the peripheral arm that includes all the known redox centers and the NADH binding site.[8] 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.[7]
Function
The protein encoded by this gene is an accessory subunit of the multisubunit NADH:ubiquinone oxidoreductase (complex I) that is not directly involved in catalysis.[7] However, NDUFB6 is required for electron transfer activity.[11] Mammalian complex I is composed of 45 different subunits. It locates at the mitochondrial inner membrane. This protein complex has NADH dehydrogenase activity and oxidoreductase activity. It transfers electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone. Alternative splicing occurs at this locus and two transcript variants encoding distinct isoforms have been identified.[7] 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.[8]
Clinical significance
Decreased expression of genes involved in oxidative phosphorylation, including NDUFB6, is associated with insulin resistance and type 2 diabetes. A polymorphism in the promoter region of the NDFUB6 gene resulting in an adenine to guanine shift at rs629566 was shown to create a DNA methylation site that is associated with a decline in NDUFB6 expression in muscle of aging patients.[12]
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^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". Cytogenetics and Cell Genetics. 82 (1–2): 115–9. doi:10.1159/000015082. PMID9763677.
^Smeitink J, Loeffen J, Smeets R, Triepels R, Ruitenbeek W, Trijbels F, van den Heuvel L (Aug 1998). "Molecular characterization and mutational analysis of the human B17 subunit of the mitochondrial respiratory chain complex I". Human Genetics. 103 (2): 245–50. doi:10.1007/s004390050813. PMID9760212.
^Loublier S, Bayot A, Rak M, El-Khoury R, Bénit P, Rustin P (Oct 2011). "The NDUFB6 subunit of the mitochondrial respiratory chain complex I is required for electron transfer activity: a proof of principle study on stable and controlled RNA interference in human cell lines". Biochemical and Biophysical Research Communications. 414 (2): 367–72. doi:10.1016/j.bbrc.2011.09.078. PMID21964293.
^Ling C, Poulsen P, Simonsson S, Rönn T, Holmkvist J, Almgren P, Hagert P, Nilsson E, Mabey AG, Nilsson P, Vaag A, Groop L (Nov 2007). "Genetic and epigenetic factors are associated with expression of respiratory chain component NDUFB6 in human skeletal muscle". The Journal of Clinical Investigation. 117 (11): 3427–35. doi:10.1172/JCI30938. PMID17948130.
Loeffen JL, Triepels RH, van den Heuvel LP, Schuelke M, Buskens CA, Smeets RJ, Trijbels JM, Smeitink JA (Dec 1998). "cDNA of eight nuclear encoded subunits of NADH:ubiquinone oxidoreductase: human complex I cDNA characterization completed". Biochemical and Biophysical Research Communications. 253 (2): 415–22. doi:10.1006/bbrc.1998.9786. PMID9878551.
Vogel RO, Dieteren CE, van den Heuvel LP, Willems PH, Smeitink JA, Koopman WJ, Nijtmans LG (Mar 2007). "Identification of mitochondrial complex I assembly intermediates by tracing tagged NDUFS3 demonstrates the entry point of mitochondrial subunits". The Journal of Biological Chemistry. 282 (10): 7582–90. doi:10.1074/jbc.M609410200. PMID17209039.{{cite journal}}: CS1 maint: unflagged free DOI (link)
