报告题目：Mechanistic Studies of Polyhydroxybutyrate (PHB) Biosynthesis
报 告 人：Ping Li, Assistant Professor
Department of Chemistry,
Kansas State University, Manhattan, KS, USA
Postdoctoral positions and graduate assistantship are available in Dr. Li’s group.
Mechanistic Studies of Polyhydroxybutyrate (PHB) Biosynthesis
PHB synthases catalyze the conversion of 3-hydroxybutyryl coenzyme A (HBCoA) to PHB with a molecular mass of 1.5 MDa. The polymerization involves covalent catalysis with a Cys. Two mechanisms for elongation have been proposed. The first involves an active site composed of two monomers in which the growing hydroxybutyrate (HB) chain alternates between Cys on each monomer. The second involves covalently attached intermediates and noncovalent (HB)nCoA intermediates. Three strategies have been developed to distinguish between these models. Our results support the mechanism involving covalently and noncovalently bound intermediates. In addition, a loading site is proposed for the priming process. Understanding the mechanism of polymerization will help us engineer PHB synthases to produce biodegradable polymers in a controlled fashion.