title: Covalent linkage mediates communication between ACP and TE domains in modular polyketide synthases.
abstract: Polyketide natural products such as erythromycin A and epothilone are assembled on multienzyme polyketide synthases (PKSs), which consist of modular sets of protein domains. Within these type I systems, the fidelity of biosynthesis depends on the programmed interaction among the multiple domains within each module, centered around the acyl carrier protein (ACP). A detailed understanding of interdomain communication will therefore be vital for attempts to reprogram these pathways by genetic engineering. We report here that the interaction between a representative ACP domain and its downstream thioesterase (TE) is mediated largely by covalent tethering through a short "linker" region, with only a minor energetic contribution from protein-protein molecular recognition. This finding helps explain in part the empirical observation that TE domains can function out of their normal context in engineered assembly lines, and supports the view that overall PKS architecture may dictate at least a subset of interdomain interactions.
authors.affiliation: Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
authors.forename: Lucky
authors.initials: L
authors.lastname: Tran
authors.forename: Manuela
authors.initials: M
authors.lastname: Tosin
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Spencer
authors.forename: Peter F
authors.initials: PF
authors.lastname: Leadlay
authors.forename: Kira J
authors.initials: KJ
authors.lastname: Weissman
mesh_terms: D000213:Acyl Carrier Protein / Q000737:chemistry* / Q000378:metabolism*; D002087:Butyrates / Q000737:chemistry / Q000378:metabolism; D002151:Calorimetry; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D013058:Mass Spectrometry; D048630:Polyketide Synthases / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020349:Surface Plasmon Resonance; D013869:Thiolester Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000213:Acyl Carrier Protein; D002087:Butyrates; D048630:Polyketide Synthases; D013869:Thiolester Hydrolases