?
FabA/Z, beta-hydroxyacyl-acyl carrier protein (ACP)-dehydratases: One of several distinct enzyme types of the dissociative, type II, fatty acid synthase system (found in bacteria and plants) required to complete successive cycles of fatty acid elongation. The third step of the elongation cycle, the dehydration of beta-hydroxyacyl-ACP to trans-2-acyl-ACP, is catalyzed by FabA or FabZ. FabA is bifunctional and catalyzes an additional isomerization reaction of trans-2-acyl-ACP to cis-3-acyl-ACP, an essential reaction to unsaturated fatty acid synthesis. FabZ is the primary dehydratase that participates in the elongation cycles of saturated as well as unsaturated fatty acid biosynthesis, whereas FabA is more active in the dehydration of beta-hydroxydecanoyl-ACP. The FabA structure is homodimeric with two independent active sites located at the dimer interface.
|