Acetyl-CoA carboxylase complex

In the cytosol, acetyl-GoA is carboxylated, producing malonyl-CoA, a key intermediate in fatty-acid biosynthesis (Figure 21.13). This reaction is catalyzed by the acetyl-CoA carboxylase complex, which consists of three enzymes and requires Mn, biotin, and ATP for activity. We have already seen that enzymes catalyzing reactions that take place in several steps frequently consist of several separate protein molecules, and this enzyme follows that pattern. In this case, acetyl-GoA carboxylase consists of the three proteins biotin carboxylase, the biotin carrier protein, and carboxyl transferase. Biotin carboxylase catalyzes the transfer... 

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