4imp

Publication Abstract from PubMed

The dimerization of multimodular polyketide synthases is essential for their function. Motifs that supplement the contacts made by dimeric polyketide synthase enzymes have previously been characterized outside the boundaries of modules, at the N- and C-terminal ends of polyketide synthase subunits. Here we describe a heretofore uncharacterized dimerization motif located within modules. The dimeric state of this dimerization element was elucidated through the 2.6 A resolution crystal structure of a fragment containing a dimerization element and a ketoreductase. The solution structure of a standalone dimerization element was revealed by nuclear magnetic resonance spectroscopy to be consistent with that of the crystal structure, and its dimerization constant was measured through analytical ultracentrifugation to be approximately 20 muM. The dimer buries approximately 990 A2 at its interface, and its C-terminal helices rigidly connect to ketoreductase domains to constrain their locations within a module. These structural restraints permitted the construction of a common type of polyketide synthase module.

The Missing Linker: A Dimerization Motif Located within Polyketide Synthase Modules.,Zheng J, Fage CD, Demeler B, Hoffman DW, Keatinge-Clay AT ACS Chem Biol. 2013 Mar 25. PMID:23489133^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.