The domains in the polyketide synthase type I:
* ACP: acyl carrier protein (serves as chaperone)
* AT: acyl transferase  (transfers acyl group form CoA to ACP)
* KS: keto synthase  (forms the new carbon-carbon bond)
* KR: keto reductase  (NADPH-dependent reduces beta-ketone to beta-hydroxyl)
* DH: dehydratase  (eliminates beta-OH to anpha/beta-unsaturation)
* ER: enoyl reductase  (NADPH-dependent reduces anpha/beta-unsaturation)
* TE: thioesterase  (hydrolyses / cyclizes)