Plant acetyl-CoA carboxylase, carboxyltransferase domain (ACCase CT domain)

Plant acetyl-CoA carboxylase (ACCase) is a vital enzyme that catalyzes the first committed and rate-limiting step in fatty acid biosynthesis: the ATP-dependent conversion of acetyl-CoA to malonyl-CoA (1.2.1, 1.4.2). The carboxyltransferase (CT) domain specifically facilitates the second half-reaction of this process, where the carboxyl group is transferred from carboxybiotin to acetyl-CoA (1.3.5, 1.4.1). In plants, particularly within the Poaceae family (grasses), the plastidic form of ACCase is a large, homomeric enzyme that is highly sensitive to several classes of herbicides, including aryloxyphenoxypropionates (FOPs), cyclohexanediones (DIMs), and phenylpyrazolines (DENs) (1.3.2, 1.5.1). These herbicides bind to the CT domain and effectively shut down lipid production, leading to the cessation of membrane synthesis and eventual plant death (1.3.3, 1.5.2). While primarily an agricultural target for selective weed control, the enzyme's central role in metabolism makes its human homologs (ACC1 and ACC2) significant targets for treating metabolic diseases such as obesity, type 2 diabetes, and cancer (1.2.2, 1.2.5). However, the plant-specific CT domain is distinguished by its unique sensitivity to these graminicides, which do not typically affect mammalian ACCase isoforms (1.3.1, 1.5.3).

Other names

Acetyl-CoA carboxylase carboxyltransferase subunitACCase CTPlastidic acetyl-CoA carboxylaseCarboxyltransferase domain of ACCaseAcetyl-CoA carboxytransferase

Inhibition of the carboxyltransferase activity of acetyl-CoA carboxylase, preventing the transfer of the carboxyl group from carboxybiotin to acetyl-CoA, thereby halting the production of malonyl-CoA and subsequent fatty acid biosynthesis (1.3.1, 1.5.1).