Polyketide synthase (PKS) catalyzes the biosynthesis of polyketides, which are structurally and functionally diverse natural products in microorganisms and plants [1]. Type I modular PKSs are the large, multifunctional enzymes responsible for the production of a diverse family of structurally rich and often biologically active natural products. The efficiency of acyl transfer at the interfaces of the individual PKS proteins is thought to be governed by helical regions, termed docking domains (dd). Two such N-terminal domains dimerise to form amphipathic parallel alpha-helical coiled coils: dimerisation is essential for protein function [1].

1: The structure of docking domains in modular polyketide synthases. Broadhurst RW, Nietlispach D, Wheatcroft MP, Leadlay PF, Weissman KJ; Chem Biol. 2003;10:723-731. PMID:12954331

2: Multimodular type I polyketide synthases in algae evolve by module duplications and displacement of AT domains in trans. Shelest E, Heimerl N, Fichtner M, Sasso S; BMC Genomics. 2015;16:1015. PMID:26611533

3: Structural basis for binding specificity between subclasses of modular polyketide synthase docking domains. Buchholz TJ, Geders TW, Bartley FE 3rd, Reynolds KA, Smith JL, Sherman DH; ACS Chem Biol. 2009;4:41-52. PMID:19146481