title: Proposed arrangement of proteins forming a bacterial type II polyketide synthase.
abstract: Aklanonic acid is synthesized by a type II polyketide synthase (PKS) composed of eight protein subunits. The network of protein interactions within this complex was investigated using a yeast two-hybrid system, by coaffinity chromatography and by two different computer-aided protein docking simulations. Results suggest that the ketosynthase (KS) alpha and beta subunits interact with each other, and that the KSalpha subunit also probably interacts with a malonyl-CoA:ACP acyltransferase (DpsD), forming a putative minimal synthase. We speculate that DpsD may physically inhibit the priming reaction, allowing the choice of propionate rather than acetate as the starter unit. We also suggest a structural role for the cyclase (DpsY) in maintaining the overall structural integrity of the complex.
authors.affiliation: School of Pharmacy, University of London, 29-39 Brunswick Square, Bloomsbury, London WC1N 1AX, UK.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Castaldo
authors.forename: Jurica
authors.initials: J
authors.lastname: Zucko
authors.forename: Sibylle
authors.initials: S
authors.lastname: Heidelberger
authors.forename: Dusica
authors.initials: D
authors.lastname: Vujaklija
authors.forename: Daslav
authors.initials: D
authors.lastname: Hranueli
authors.forename: John
authors.initials: J
authors.lastname: Cullum
authors.forename: Pakorn
authors.initials: P
authors.lastname: Wattana-Amorn
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Crump
authors.forename: John
authors.initials: J
authors.lastname: Crosby
authors.forename: Paul F
authors.initials: PF
authors.lastname: Long
mesh_terms: D000880:Anthraquinones / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002846:Chromatography, Affinity; D003198:Computer Simulation; D008958:Models, Molecular; D048630:Polyketide Synthases / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D020798:Two-Hybrid System Techniques
chemical_list: D000880:Anthraquinones; D001426:Bacterial Proteins; D048630:Polyketide Synthases; C042374:aklanonic acid