PROFILPELAJAR.COM

NDUFB9
Identifiers
Aliases	NDUFB9, B22, CI-B22, LYRM3, UQOR22, NADH:ubiquinone oxidoreductase subunit B9, MC1DN24
External IDs	OMIM: 601445; MGI: 1913468; HomoloGene: 3669; GeneCards: NDUFB9; OMA:NDUFB9 - orthologs
Gene location (Human)
Chr.	Chromosome 8 (human)
End	124,580,648 bp
Gene location (Mouse)
Chr.	Chromosome 15 (mouse)
End	58,811,337 bp
RNA expression pattern
	Top expressed in
	myocardium of left ventricle; ; cardiac muscle tissue of right atrium; ; tibialis anterior muscle; ; quadriceps femoris muscle; ; mucosa of ileum; ; vastus lateralis muscle; ; body of tongue; ; deltoid muscle; ; right ventricle; ; lateral nuclear group of thalamus;
	Top expressed in
	facial motor nucleus; ; Paneth cell; ; masseter muscle; ; aortic valve; ; digastric muscle; ; extraocular muscle; ; myocardium of ventricle; ; sternocleidomastoid muscle; ; temporal muscle; ; thoracic diaphragm;
	More reference expression data
	n/a
Gene ontology
Molecular function	NADH dehydrogenase (ubiquinone) activity; protein binding;
Cellular component	mitochondrial inner membrane; mitochondrial respiratory chain complex I; respirasome; membrane; mitochondrion;
Biological process	hearing; mitochondrial electron transport, NADH to ubiquinone; mitochondrial respiratory chain complex I assembly;
	Sources:Amigo / QuickGO
Orthologs
	4715
	66218
	ENSG00000147684
	ENSMUSG00000022354
	Q9Y6M9
	Q9CQJ8
	NM_005005; NM_001278645; NM_001278646; NM_001311168
	NM_023172; NM_001364808
	NP_001265574; NP_001265575; NP_001298097; NP_004996
	NP_075661; NP_001351737
	Wikidata
View/Edit Human	View/Edit Mouse

NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 9 is an enzyme that in humans is encoded by the NDUFB9 gene.^[5]^[6] NADH dehydrogenase (ubiquinone) 1 beta subcomplex subunit 9 is an accessory subunit of the NADH dehydrogenase (ubiquinone) complex, located in the mitochondrial inner membrane. It is also known as Complex I and is the largest of the five complexes of the electron transport chain.^[7]

Structure

The NDUFB9 gene is located on the q arm of chromosome 8 in position 13.3 and is 10,884 base pairs long. The NDUFB9 protein weighs 22 kDa and is composed of 179 amino acids.^[8]^[9] NDUFB9 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.^[7] 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.^[6]

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. 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.^[6] 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.^[7]

Clinical significance

A mutation in NDUFB9 resulting in reduction in NDUFB9 protein and both amount and activity of complex I has been shown to be a causal mutation leading to Complex I deficiency.^[10]

References

^ ^a ^b ^c GRCh38: Ensembl release 89: ENSG00000147684 – Ensembl, May 2017
^ ^a ^b ^c GRCm38: Ensembl release 89: ENSMUSG00000022354 – Ensembl, May 2017
^ "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.
^ Gu JZ, Lin X, Wells DE (Sep 1996). "The human B22 subunit of the NADH-ubiquinone oxidoreductase maps to the region of chromosome 8 involved in branchio-oto-renal syndrome". Genomics. 35 (1): 6–10. doi:10.1006/geno.1996.0316. PMID 8661098.
^ ^a ^b ^c "Entrez Gene: NDUFB9 NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 9, 22kDa".
^ ^a ^b ^c Voet DM, Voet JG, Pratt CW (2013). "Chapter 18". Fundamentals of biochemistry: life at the molecular level (4th ed.). Hoboken, NJ: Wiley. pp. 581–620. ISBN 978-0-470-54784-7.
^ Zong NC, Li H, Li H, Lam MP, Jimenez RC, Kim CS, et al. (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.
^ "NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 9". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB).
^ Haack TB, Madignier F, Herzer M, Lamantea E, Danhauser K, Invernizzi F, et al. (February 2012). "Mutation screening of 75 candidate genes in 152 complex I deficiency cases identifies pathogenic variants in 16 genes including NDUFB9". Journal of Medical Genetics. 49 (2): 83–89. doi:10.1136/jmedgenet-2011-100577. PMID 22200994. S2CID 13907809.

Emahazion T, Beskow A, Gyllensten U, Brookes AJ (1998). "Intron based radiation hybrid mapping of 15 complex I genes of the human electron transport chain". Cytogenetics and Cell Genetics. 82 (1–2): 115–119. doi:10.1159/000015082. PMID 9763677. S2CID 46818955.
Loeffen JL, Triepels RH, van den Heuvel LP, Schuelke M, Buskens CA, Smeets RJ, et al. (December 1998). "cDNA of eight nuclear encoded subunits of NADH:ubiquinone oxidoreductase: human complex I cDNA characterization completed". Biochemical and Biophysical Research Communications. 253 (2): 415–422. doi:10.1006/bbrc.1998.9786. PMID 9878551.
Lin X, Wells DE, Kimberling WJ, Kumar S (March 1999). "Human NDUFB9 gene: genomic organization and a possible candidate gene associated with deafness disorder mapped to chromosome 8q13". Human Heredity. 49 (2): 75–80. doi:10.1159/000022848. PMID 10077726. S2CID 25197216.
Dias Neto E, Correa RG, Verjovski-Almeida S, Briones MR, Nagai MA, da Silva W, et al. (March 2000). "Shotgun sequencing of the human transcriptome with ORF expressed sequence tags". Proceedings of the National Academy of Sciences of the United States of America. 97 (7): 3491–3496. Bibcode:2000PNAS...97.3491D. doi:10.1073/pnas.97.7.3491. PMC 16267. PMID 10737800.
Ye Z, Connor JR (August 2000). "cDNA cloning by amplification of circularized first strand cDNAs reveals non-IRE-regulated iron-responsive mRNAs". Biochemical and Biophysical Research Communications. 275 (1): 223–227. doi:10.1006/bbrc.2000.3282. PMID 10944468.
Zhang QH, Ye M, Wu XY, Ren SX, Zhao M, Zhao CJ, et al. (October 2000). "Cloning and functional analysis of cDNAs with open reading frames for 300 previously undefined genes expressed in CD34+ hematopoietic stem/progenitor cells". Genome Research. 10 (10): 1546–1560. doi:10.1101/gr.140200. PMC 310934. PMID 11042152.
Stelzl U, Worm U, Lalowski M, Haenig C, Brembeck FH, Goehler H, et al. (September 2005). "A human protein-protein interaction network: a resource for annotating the proteome". Cell. 122 (6): 957–968. doi:10.1016/j.cell.2005.08.029. hdl:11858/00-001M-0000-0010-8592-0. PMID 16169070. S2CID 8235923.
Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, et al. (October 2005). "Towards a proteome-scale map of the human protein-protein interaction network". Nature. 437 (7062): 1173–1178. Bibcode:2005Natur.437.1173R. doi:10.1038/nature04209. PMID 16189514. S2CID 4427026.