Polyhydroxybutyrate synthase

In order to produce PHAs in plants it is necessary to introduce the biosynthetic enzymes from bacteria. PHB represents the best characterized and simplest form of PHA, and the synthetic pathway (Figure 4.2) has been extensively studied in Ralstonia eutropha. 30,31 Starting from acetyl-CoA, a P-ketothiolase is required in order to form acetoacetyl-CoA. This is then reduced by a NADPH-dependent acetoacetyl-CoA reductase, which gives rise to 3-hydroxybutyryl-CoA. The latter intermediate is the substrate for the polymerization reaction catalyzed by polyhydroxybutyrate synthase.30 In Ralstonia eutropha, the thiolase, reductase, and synthase genes make up an operon.31... 

Hoppensack, A., Rehm, B.H.A., and Steinbiichel, A. (1999) Analysis of 4-phosphopantetheinylation of polyhydroxybutyrate synthase from Ralstonia eutropha generation of beta-alanine auxotrophic Tn5 mutants and cloning of the panD gene region. J. Bacteriol., 181, 1429-1435. 

Hezayen FF, Steinbiichel A, Rehm BH (2002) Biochemical and enzymological properties of the polyhydroxybutyrate synthase from the extremely halophiUc archaeon strain 56. Arch Biochem Biophys 403 284-291... 

Leaf, T. A., Peterson, M. S., Stoup, S. K., Somers, D., and Srienc, R (1996). Saccharomyces cerevi-siae expressing bacterial polyhydroxybutyrate synthase produces poly-3-hydroxybutyrate. Microbiology 42, 1169-1180. 

Leaf TA, Peterson MS, Stoup SK, Somers D, Srienc F (1996) Saccharomyces cerevisiae expressing bacterial polyhydroxybutyrate synthase produces poly-3-hydroxybutyrate. Microbiol 142 1169-1180 Lee SY (1996a) Bacterial polyhydroxyalkanoates. Biotechnol Bioeng 49 1-14 Lee SY (1996b) Plastic bacteria Progress and prospects for polyhydroxyalkanoate production in bacteria. Trends Biotechnol 14 431 38 Lee SY (1997) E. coli moves into the plastic age. Nat Biotechnol 15 17-18 Lee SY, Chang HN (1995a) Production of poly(hydroxyalkanoic acid). Adv Biochem Eng Biotechnol 52 27-58... 

Sinskey, A.)., and Stubbe,). (2000) Lipases provide a new mechanistic model for polyhydroxybutyrate (PHB) synthases characterization of the functional residues in Chromatium vinosum PHB synthase. Biochemistry, 39, 3927-3936. 

PHA synthase Phasin protein PHA depolymerase Polyhydroxybutyrate Polylactic acid Pahn oil mill effluent... 

Two types of polyhydroxyalkanoate (PHA) biosynthesis gene loci (phb and pha) of Pseudomonas sp. strain 61-3, which produces a blend of poly-3-hydroxybutyrate [PHB] homopolymer and a random copolymer poly(3-hydroxybutyrate-co-3-hydroxyalkanoate) [P(3HB-co-3HA] consisting of 3HA units of 4 to 12 carbon atoms, were cloned and analyzed at the molecular level [274]. In the phb locus, three open reading frames encoding polyhydroxybutyrate (PHB) synthase (PhbCPs), 6-ketothiolase (PhbAPs), and NADPH-dependent acetoacetyl coenzyme A reductase (PhbBPs) were... 

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