This is the catalytic domain of alcohol dehydrogenases. Many of them contain an inserted zinc binding domain. This domain has a GroES-like structure [1-2].
2-enoyl thioester reductases catalyse the reduction of trans-2-enoyl acyl carrier protein/coenzyme A to acyl carrier protein/coenzyme A. Yeast enzymes, such as Etr1p and Mrf1p, are responsible for the NADPH dependent reaction in mitochondrial fatty acid synthesis, and are indispensible for respiratory function in yeast. They belong to the medium chain dehydrogenases/reductases (MDR) superfamily and are structurally distinguishable from the prokaryotic 2-enoyl thioester which belong to the short chain dehydrogenases/reductases (SDR) superfamily. The Candida tropicalis genes ETR1 and ETR2 both encode enzymatically active 2-enoyl thioester reductases, which can form both homodimers and heterodimers.