Glutaryl-CoA dehydrogenase

Last updated
GCDH
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases GCDH , ACAD5, GCD, glutaryl-CoA dehydrogenase, Glutaryl-Coenzyme A dehydrogenase
External IDs OMIM: 608801 MGI: 104541 HomoloGene: 130 GeneCards: GCDH
Gene location (Human)
Ideogram human chromosome 19.svg
Chr. Chromosome 19 (human) [1]
Human chromosome 19 ideogram.svg
HSR 1996 II 3.5e.svg
Red rectangle 2x18.png
Band 19p13.13Start12,891,160 bp [1]
End12,914,207 bp [1]
Orthologs
SpeciesHumanMouse
Entrez

2639

270076

Ensembl

ENSG00000105607

ENSMUSG00000003809

UniProt

Q92947

Q60759

RefSeq (mRNA)

NM_000159
NM_013976

NM_001044744
NM_008097

RefSeq (protein)

NP_000150
NP_039663

NP_001038209
NP_032123

Location (UCSC) Chr 19: 12.89 – 12.91 Mb Chr 8: 84.89 – 84.89 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse
glutaryl-CoA dehydrogenase (decarboxylating)
Identifiers
EC number 1.3.8.6
CAS number 37255-38-2
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum

Glutaryl-CoA dehydrogenase (GCDH) is an enzyme encoded by the GCDH gene on chromosome 19. The protein belongs to the acyl-CoA dehydrogenase family (ACD). It catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and carbon dioxide in the degradative pathway of L-lysine, L-hydroxylysine, and L-tryptophan metabolism. It uses electron transfer flavoprotein as its electron acceptor. The enzyme exists in the mitochondrial matrix as a homotetramer of 45-kD subunits. Mutations in this gene result in the metabolic disorder glutaric aciduria type 1, which is also known as glutaric acidemia type I. Alternative splicing of this gene results in multiple transcript variants. [5]

Contents

Structure

GCDH is a tetramer with tetrahedral symmetry, which allows it to be seen as a dimer of dimers. Its structure is very similar to other ACDs but the overall polypeptide fold of the GCDH is made up of three domains: an alpha-helical bundle amino-terminal domain, a beta-sheet domain in the middle, and another alpha-helical domain at the carboxyl terminus. The flavin adenine dinucleotide (FAD) is located at the junction between the middle beta-strand and the carboxyl terminal alpha-helix domain of one subunit and the carboxyl-terminal domain of the neighboring subunit. The most distinct difference between GCDH and other ACDs in terms of structure is the carboxyl and amino-terminal regions of the monomer and in the loop between beta-strands 4 and 5 because it is only made up of four residues, whereas other ACDs have much more. The substrate-binding pocket is filled with a string of three water molecules, which gets displaced when the substrate binds to the enzyme. The binding pocket is also smaller than some of the other ACD binding pockets because it is responsible for the chain-length specificity of GCDH for alternate substrates. [6] The GCDH gene is mapped onto 19p13.2 and has an exon count of 15. [7]

Function

GCDH is mainly known for the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and carbon dioxide, which is common in the mitochondrial oxidation of lysine, tryptophan, and hydroxylysine. The way it completes this task is through a series of physical, chemical, and electron-transfer steps. It first binds glutaryl-CoA substrate to the oxidized form of the enzyme and abstracts the alpha-proton of the substrate by the Glu370 catalytic base. Hydride is then transferred from the beta-carbon of the substrate to the N(5) of the FAD, yielding the 2e−-reduced form of FAD. Thus, this allows for the decarboxylation of glutaconyl-CoA, an enzyme-bound intermediate, by breaking the Cγ-Cδ bond, resulting in formation of a dienolate anion, a proton, and CO2. The dienolate intermediate is protonated, resulting in crotonyl-CoA and a release of products from the active site. Finally, the 2e−-reduced form of FAD is oxidized to two 1e− steps by an external electron acceptor to complete the turnover. [8]

Clinical significance

Mutations in the GCDH gene can lead to defects in the enzyme encoded by it which leads to the formation and accumulation of the metabolites glutaric acid and 3-hydroxyglutaric acid as well as glutarylcarnitine in body fluids, which essentially leads to glutaric aciduria type I, an autosomal recessive metabolic disorder. Symptoms for this disease include: macrocephaly, acute encephalitis-like crises, spasticity, dystonia, choreoathetosis, ataxia, dyskinesia and seizure and are prevalent one in every 100,000 individuals. [7] Mutations in the carboxyl-terminal of GCDH have been most identified in patients with glutaric aciduria type I; more specifically, mutations in Ala389Val, Ala389Glu, Thr385Met, Ala377Val, and Ala377Thr all seem to be associated with the disorder because they dissociate to inactive monomers and/or dimers. [6]

Interactions

GCDH has been seen to interact with:

Related Research Articles

Isocitrate dehydrogenase

Isocitrate dehydrogenase (IDH) (EC 1.1.1.42) and (EC 1.1.1.41) is an enzyme that catalyzes the oxidative decarboxylation of isocitrate, producing alpha-ketoglutarate (α-ketoglutarate) and CO2. This is a two-step process, which involves oxidation of isocitrate (a secondary alcohol) to oxalosuccinate (a ketone), followed by the decarboxylation of the carboxyl group beta to the ketone, forming alpha-ketoglutarate. In humans, IDH exists in three isoforms: IDH3 catalyzes the third step of the citric acid cycle while converting NAD+ to NADH in the mitochondria. The isoforms IDH1 and IDH2 catalyze the same reaction outside the context of the citric acid cycle and use NADP+ as a cofactor instead of NAD+. They localize to the cytosol as well as the mitochondrion and peroxisome.

Glutaric acidemia type 1 is an inherited disorder in which the body is unable to completely break down the amino acids lysine, hydroxylysine and tryptophan. Excessive levels of their intermediate breakdown products can accumulate and cause damage to the brain, but particularly the basal ganglia, which are regions that help regulate movement. GA1 causes secondary carnitine deficiency, as glutaric acid, like other organic acids, is detoxified by carnitine. Mental retardation may also occur.

Pyruvate decarboxylase

Pyruvate decarboxylase is a homotetrameric enzyme that catalyses the decarboxylation of pyruvic acid to acetaldehyde and carbon dioxide in the cytoplasm of prokaryotes, and in the cytoplasm and mitochondria of eukaryotes. It is also called 2-oxo-acid carboxylase, alpha-ketoacid carboxylase, and pyruvic decarboxylase. In anaerobic conditions, this enzyme is part of the fermentation process that occurs in yeast, especially of the genus Saccharomyces, to produce ethanol by fermentation. It is also present in some species of fish where it permits the fish to perform ethanol fermentation when oxygen is scarce. Pyruvate decarboxylase starts this process by converting pyruvate into acetaldehyde and carbon dioxide. Pyruvate decarboxylase depends on cofactors thiamine pyrophosphate (TPP) and magnesium. This enzyme should not be mistaken for the unrelated enzyme pyruvate dehydrogenase, an oxidoreductase, that catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA.

The branched-chain α-ketoacid dehydrogenase complex is a multi-subunit complex of enzymes that is found on the mitochondrial inner membrane. This enzyme complex catalyzes the oxidative decarboxylation of branched, short-chain alpha-ketoacids. BCKDC is a member of the mitochondrial α-ketoacid dehydrogenase complex family comprising pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, key enzymes that function in the Krebs cycle.

Acyl-CoA dehydrogenases (ACADs) are a class of enzymes that function to catalyze the initial step in each cycle of fatty acid β-oxidation in the mitochondria of cells. Their action results in the introduction of a trans double-bond between C2 (α) and C3 (β) of the acyl-CoA thioester substrate. Flavin adenine dinucleotide (FAD) is a required co-factor in addition to the presence of an active site glutamate in order for the enzyme to function.

SDHA

Succinate dehydrogenase complex, subunit A, flavoprotein variant is a protein that in humans is encoded by the SDHA gene. This gene encodes a major catalytic subunit of succinate-ubiquinone oxidoreductase, a complex of the mitochondrial respiratory chain. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. SDHA contains the FAD binding site where succinate is deprotonated and converted to fumarate. Mutations in this gene have been associated with a form of mitochondrial respiratory chain deficiency known as Leigh Syndrome. A pseudogene has been identified on chromosome 3q29. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.

Electron-transferring-flavoprotein dehydrogenase

Electron-transferring-flavoprotein dehydrogenase is an enzyme that transfers electrons from electron-transferring flavoprotein in the mitochondrial matrix, to the ubiquinone pool in the inner mitochondrial membrane. It is part of the electron transport chain. The enzyme is found in both prokaryotes and eukaryotes and contains a flavin and FE-S cluster. In humans, it is encoded by the ETFDH gene. Deficiency in ETF dehydrogenase causes the human genetic disease multiple acyl-CoA dehydrogenase deficiency.

Electron-transferring flavoprotein

An electron transfer flavoprotein (ETF) or electron transfer flavoprotein complex (CETF) is a flavoprotein located on the matrix face of the inner mitochondrial membrane and functions as a specific electron acceptor for primary dehydrogenases, transferring the electrons to terminal respiratory systems such as electron-transferring-flavoprotein dehydrogenase. They can be functionally classified into constitutive, "housekeeping" ETFs, mainly involved in the oxidation of fatty acids, and ETFs produced by some prokaryotes under specific growth conditions, receiving electrons only from the oxidation of specific substrates.

ETFA

The human ETFA gene encodes the Electron-transfer-flavoprotein, alpha subunit, also known as ETF-α. Together with Electron-transfer-flavoprotein, beta subunit, encoded by the 'ETFB' gene, it forms the heterodimericElectron transfer flavoprotein (ETF). The native ETF protein contains one molecule of FAD and one molecule of AMP, respectively.

ETFB

The human ETFB gene encodes the Electron-transfer-flavoprotein, beta subunit, also known as ETF-β. Together with Electron-transfer-flavoprotein, alpha subunit, encoded by the 'ETFA' gene, it forms the heterodimeric Electron transfer flavoprotein (ETF). The native ETF protein contains one molecule of FAD and one molecule of AMP, respectively.

IDH3B

Isocitrate dehydrogenase [NAD] subunit beta, mitochondrial is an enzyme that in humans is encoded by the IDH3B gene.

NDUFB6

NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 6, also known as complex I-B17, is a protein that in humans is encoded by the NDUFB6 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex subunit 6, 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.

NDUFA8

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 8 is an enzyme that in humans is encoded by the NDUFA8 gene. The NDUFA8 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.

NDUFA12

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 12 is an enzyme that in humans is encoded by the NDUFA12 gene. The NDUFA12 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. Mutations in subunits of NADH dehydrogenase (ubiquinone), also known as Complex I, frequently lead to complex neurodegenerative diseases such as Leigh's syndrome that result from mitochondrial complex I deficiency.

Malate dehydrogenase 2

Malate dehydrogenase, mitochondrial also known as malate dehydrogenase 2 is an enzyme that in humans is encoded by the MDH2 gene.

ETFDH

Electron transfer flavoprotein-ubiquinone oxidoreductase, mitochondrial is an enzyme that in humans is encoded by the ETFDH gene. This gene encodes a component of the electron-transfer system in mitochondria and is essential for electron transfer from a number of mitochondrial flavin-containing dehydrogenases to the main respiratory chain.

NDUFB11

NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 11, mitochondrial is an enzyme that in humans is encoded by the NDUFB11 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex subunit 11 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. NDUFB11 mutations have been associated with linear skin defects with multiple congenital anomalies 3 and mitochondrial complex I deficiency.

NDUFB3

NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 3, 12kDa is a protein that in humans is encoded by the NDUFB3 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 3, 12kDa 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. Mutations in this gene contribute to mitochondrial complex I deficiency.

DHTKD1

Dehydrogenase E1 and transketolase domain containing 1 is a protein that in humans is encoded by the DHTKD1 gene. This gene encodes a component of a mitochondrial 2-oxoglutarate-dehydrogenase-complex-like protein involved in the degradation pathways of several amino acids, including lysine. Mutations in this gene are associated with 2-aminoadipic 2-oxoadipic aciduria and Charcot-Marie-Tooth Disease Type 2Q.

NDUFB4

NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 4, 15kDa is a protein that in humans is encoded by the NDUFB4 gene. The NDUFB4 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.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000105607 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000003809 - Ensembl, May 2017
  3. ↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ↑ "GCDH glutaryl-CoA dehydrogenase [ Homo sapiens (human) ]". NCBI. Retrieved 6 August 2015.
  6. 1 2 Fu Z, Wang M, Paschke R, Rao KS, Frerman FE, Kim JJ (August 2004). "Crystal structures of human glutaryl-CoA dehydrogenase with and without an alternate substrate: structural bases of dehydrogenation and decarboxylation reactions". Biochemistry. 43 (30): 9674–84. doi:10.1021/bi049290c. PMID   15274622.
  7. 1 2 Georgiou T, Nicolaidou P, Hadjichristou A, Ioannou R, Dionysiou M, Siama E, Chappa G, Anastasiadou V, Drousiotou A (September 2014). "Molecular analysis of Cypriot patients with Glutaric aciduria type I: identification of two novel mutations". Clinical Biochemistry. 47 (13–14): 1300–5. doi:10.1016/j.clinbiochem.2014.06.017. PMID   24973495.
  8. ↑ Rao KS, Albro M, Dwyer TM, Frerman FE (December 2006). "Kinetic mechanism of glutaryl-CoA dehydrogenase". Biochemistry. 45 (51): 15853–61. doi:10.1021/bi0609016. PMID   17176108.

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