gamma-butyrobetaine dioxygenase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: 2-oxoglutarate + 4-(trimethylammonio)butanoate + O2 = carnitine + CO2 + succinate. [EC:1.14.11.1, RHEA:24028]

Gamma-butyrobetaine dioxygenase (GBSD) is an enzyme responsible for the crucial step in the biosynthesis of L-carnitine, a vital nutrient involved in fatty acid metabolism. Specifically, GBSD catalyzes the oxygen-dependent oxidation of gamma-butyrobetaine, a precursor to carnitine, into 4-hydroxybutyrobetaine. This oxidative process involves the incorporation of molecular oxygen into the substrate, resulting in the formation of a hydroxyl group at the 4-position of the butyrobetaine molecule. The reaction occurs in a two-step mechanism. First, GBSD binds both gamma-butyrobetaine and oxygen, forming a complex. Then, GBSD facilitates the transfer of an oxygen atom from molecular oxygen to gamma-butyrobetaine, leading to the production of 4-hydroxybutyrobetaine and water. This enzymatic reaction requires the presence of iron ions, which act as cofactors in the active site of GBSD. The iron ions facilitate the transfer of electrons during the oxidation process. GBSD activity plays a pivotal role in carnitine biosynthesis, which is essential for the transport of long-chain fatty acids across mitochondrial membranes. This process is crucial for energy production, as fatty acids serve as an important source of fuel in many tissues. Furthermore, carnitine is involved in other cellular processes, such as muscle function and detoxification. Deficiencies in GBSD activity can lead to carnitine deficiency, which can manifest in a range of clinical symptoms, including muscle weakness, fatigue, and impaired cognitive function. Therefore, understanding the molecular function of GBSD is essential for comprehending the role of carnitine in human health and disease.'
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Proteins (2)

Compounds (8)