acetyl-CoA carboxylase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: ATP + acetyl-CoA + HCO3- = ADP + phosphate + malonyl-CoA. [EC:6.4.1.2]

Acetyl-CoA carboxylase (ACC) activity catalyzes the irreversible carboxylation of acetyl-CoA to malonyl-CoA. This reaction is the committed step in fatty acid biosynthesis and is essential for the synthesis of all fatty acids in the body. The enzyme utilizes bicarbonate as the source of carbon dioxide, which is first activated by ATP to form carboxyphosphate. The carboxyphosphate then reacts with biotin, a cofactor tightly bound to the enzyme, to form carboxybiotin. The carboxybiotin group is then transferred to acetyl-CoA, forming malonyl-CoA. This reaction is highly regulated and is subject to both allosteric and covalent modification. ACC is a large, multi-domain protein with two active sites: a biotin carboxylase domain and a carboxyltransferase domain. The biotin carboxylase domain binds biotin and catalyzes the formation of carboxybiotin. The carboxyltransferase domain binds both acetyl-CoA and carboxybiotin and catalyzes the transfer of the carboxyl group from carboxybiotin to acetyl-CoA. ACC is a key regulatory enzyme in fatty acid metabolism, and its activity is tightly controlled by a variety of factors, including the availability of substrates, hormones, and cellular energy status. In addition to its role in fatty acid biosynthesis, ACC also plays a role in other metabolic processes, such as the synthesis of cholesterol, ketone bodies, and certain amino acids.'
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Proteins (3)

Compounds (2)