Acetoacetyl-CoA reductases in Cupriavidus necator

Polyhydroxyalkanoates (phas) have been recognized as good substitutes for the non-biodegradable and petrochemically produced polymers. nadph-dependent acetoacetyl-coenzyme a (acetoacetyl-coa) reductase (phab) is one of the key enzyme in the synthesis of poly(3-hydroxybutyrate) [p(3hb)],along with β-ketothiolase (phaa) and polyhydroxyalkanoate synthase (phac). the phab-encoding gene has been reported in many bacteria,including cupriavidus necator,and is usually located in the phb operon together with β-ketothiolase (phaa) and pha synthase (phac). in present study pha-specific acetoacetyl-coa reductase (phab) was studied on the basis of available sequences in various database to understand their diversity.