FIGURE 17-12 Oxidation of propionyl-CoA produced by oxidation of odd-number fatty acids

Step 1

First, propionyl-CoA carboxylase (with biotin as a cofactor) carboxylates it to D-methylmalonyl-CoA.

Step 2

This is epimerized to the L-isomer by methylmalonyl-CoA epimerase.

Step 3

methylmalonyl-CoA mutase, using coenzyme B12, rearranges it into succinyl-CoA, which can enter the citric acid cycle. ATP provides energy for the initial carboxylation.

Image