... 6-deoxyerythronolide B synthase; DKS, diketide synthase; FAS, fatty acid synthase;KR, ketoreductase; KS, ketosynthase; PKS, polyketide synthase; SNAC, thioester of N-acetylcysteamine; TE, thioesterase.* [Correction ... general basis of regulation in PKS operations, especially in morefully evolved systems, such as the DEBS. The proposalthat there are two forms of control resulting from highlevels of occupancy of ... Leadlay PF (1999) Molecu-lar basis of Celmer’s rules: the role of two ketoreductasedomains in the control of chirality by the erythromycinmodular polyketide synthase. Chem Biol 6, 189–195.42...