N-acetylornithine carbamoyltransferase

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N-acetylornithine carbamoyltransferase
Identifiers
EC no. 2.1.3.9
CAS no. 890853-54-0
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MetaCyc metabolic pathway
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In enzymology, a N-acetylornithine carbamoyltransferase (EC 2.1.3.9) is an enzyme that catalyzes the chemical reaction

carbamoyl phosphate + N2-acetyl-L-ornithine phosphate + N-acetyl-L-citrulline

Thus, the two substrates of this enzyme are carbamoyl phosphate and N2-acetyl-L-ornithine, whereas its two products are phosphate and N-acetyl-L-citrulline.

This enzyme belongs to the family of transferases that transfer one-carbon groups, specifically the carboxy- and carbamoyltransferases. The systematic name of this enzyme class is carbamoyl-phosphate:N2-acetyl-L-ornithine carbamoyltransferase. Other names in common use include acetylornithine transcarbamylase, N-acetylornithine transcarbamylase, AOTC, and carbamoyl-phosphate:2-N-acetyl-L-ornithine carbamoyltransferase.

Structural studies

As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 2G65, 2G68, 2G6A, and 2G6C.

Related Research Articles

The urea cycle (also known as the ornithine cycle) is a cycle of biochemical reactions that produces urea (NH2)2CO from ammonia (NH3). Animals that use this cycle, mainly amphibians and mammals, are called ureotelic.

<span class="mw-page-title-main">Ornithine transcarbamylase</span> Mammalian protein found in Homo sapiens

Ornithine transcarbamylase (OTC) is an enzyme that catalyzes the reaction between carbamoyl phosphate (CP) and ornithine (Orn) to form citrulline (Cit) and phosphate (Pi). There are two classes of OTC: anabolic and catabolic. This article focuses on anabolic OTC. Anabolic OTC facilitates the sixth step in the biosynthesis of the amino acid arginine in prokaryotes. In contrast, mammalian OTC plays an essential role in the urea cycle, the purpose of which is to capture toxic ammonia and transform it into urea, a less toxic nitrogen source, for excretion.

<span class="mw-page-title-main">Carbamoyl phosphate</span> Chemical compound

Carbamoyl phosphate is an anion of biochemical significance. In land-dwelling animals, it is an intermediary metabolite in nitrogen disposal through the urea cycle and the synthesis of pyrimidines. Its enzymatic counterpart, carbamoyl phosphate synthetase I, interacts with a class of molecules called sirtuins, NAD dependent protein deacetylases, and ATP to form carbamoyl phosphate. CP then enters the urea cycle in which it reacts with ornithine to form citrulline.

<span class="mw-page-title-main">Aspartate carbamoyltransferase</span> Protein family

Aspartate carbamoyltransferase catalyzes the first step in the pyrimidine biosynthetic pathway.

<span class="mw-page-title-main">Hyperammonemia</span> Medical condition

Hyperammonemia is a metabolic disturbance characterised by an excess of ammonia in the blood. It is a dangerous condition that may lead to brain injury and death. It may be primary or secondary.

<span class="mw-page-title-main">Ornithine transcarbamylase deficiency</span> Medical condition

Ornithine transcarbamylase deficiency also known as OTC deficiency is the most common urea cycle disorder in humans. Ornithine transcarbamylase, the defective enzyme in this disorder is the final enzyme in the proximal portion of the urea cycle, responsible for converting carbamoyl phosphate and ornithine into citrulline. OTC deficiency is inherited in an X-linked recessive manner, meaning males are more commonly affected than females.

In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.

<span class="mw-page-title-main">Mitochondrial matrix</span> Space within the inner membrane of the mitochondrion

In the mitochondrion, the matrix is the space within the inner membrane. The word "matrix" stems from the fact that this space is viscous, compared to the relatively aqueous cytoplasm. The mitochondrial matrix contains the mitochondrial DNA, ribosomes, soluble enzymes, small organic molecules, nucleotide cofactors, and inorganic ions.[1] The enzymes in the matrix facilitate reactions responsible for the production of ATP, such as the citric acid cycle, oxidative phosphorylation, oxidation of pyruvate, and the beta oxidation of fatty acids.

<i>N</i>-Acetylglutamic acid Chemical compound

N-Acetylglutamic acid (also referred to as N-acetylglutamate, abbreviated NAG, chemical formula C7H11NO5) is biosynthesized from glutamate and acetylornithine by ornithine acetyltransferase, and from glutamic acid and acetyl-CoA by the enzyme N-acetylglutamate synthase. The reverse reaction, hydrolysis of the acetyl group, is catalyzed by a specific hydrolase. It is the first intermediate involved in the biosynthesis of arginine in prokaryotes and simple eukaryotes and a regulator in the process known as the urea cycle that converts toxic ammonia to urea for excretion from the body in vertebrates.

<i>N</i>-Acetylglutamate synthase Class of enzymes

N-Acetylglutamate synthase (NAGS) is an enzyme that catalyses the production of N-acetylglutamate (NAG) from glutamate and acetyl-CoA.

<span class="mw-page-title-main">N-Acetylglutamate synthase deficiency</span> Medical condition

N-Acetylglutamate synthase deficiency is an autosomal recessive urea cycle disorder.

In enzymology, a lysine carbamoyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, an oxamate carbamoyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, a putrescine carbamoyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, an acetylornithine deacetylase (EC 3.5.1.16) is an enzyme that catalyzes the chemical reaction

In enzymology, a glutamate N-acetyltransferase (EC 2.3.1.35) is an enzyme that catalyzes the chemical reaction

In enzymology, an acetylornithine transaminase (EC 2.6.1.11) is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">ATCase/OTCase family</span>

In molecular biology, the ATCase/OTCase family is a protein family which contains two related enzymes: aspartate carbamoyltransferase EC 2.1.3.2 and ornithine carbamoyltransferase EC 2.1.3.3. It has been shown that these enzymes are evolutionary related. The predicted secondary structure of both enzymes is similar and there are some regions of sequence similarities. One of these regions includes three residues which have been shown, by crystallographic studies to be implicated in binding the phosphoryl group of carbamoyl phosphate and may also play a role in trimerisation of the molecules. The N-terminal domain is the carbamoyl phosphate binding domain. The C-terminal domain is an aspartate/ornithine-binding domain.

N-succinylornithine carbamoyltransferase (EC 2.1.3.11, succinylornithine transcarbamylase, N-succinyl-L-ornithine transcarbamylase, SOTCase) is an enzyme with systematic name carbamoyl phosphate:N2-succinyl-L-ornithine carbamoyltransferase. This enzyme catalyses the following chemical reaction

Arginine and proline metabolism is one of the central pathways for the biosynthesis of the amino acids arginine and proline from glutamate. The pathways linking arginine, glutamate, and proline are bidirectional. Thus, the net utilization or production of these amino acids is highly dependent on cell type and developmental stage. Altered proline metabolism has been linked to metastasis formation in breast cancer.

References