Poly-beta-hydroxybutyrate (PHB) biosynthetic genes in Rhizobium meliloti 41

Microbiology. 1995 Oct;141 ( Pt 10):2553-9. doi: 10.1099/13500872-141-10-2553.


Genes encoding beta-ketothiolase (phaA), acetoacetyl-CoA reductase (phaB) and PHB-synthase (phaC) from R. meliloti 41, together with a fourth gene, referred to as ORF1, presumed to be involved in PHB biosynthesis, have been cloned and sequenced. phaA, phaB and ORF1 were identified by heterologous hybridization on a cosmid library, while phaC was isolated by cloning the transposon-tagged fragment from a R. meliloti PHB- Tn5 mutant. phaA and phaB were functionally expressed in Escherichia coli while phaC was able to complement a PHB- strain of R. meliloti 41. The three genes were sufficient to direct the production of polyhydroxyalkanoate in E. coli. The homology of ORF1 with an ORF located near the PHB genes in two phototrophic bacteria suggests its involvement in PHB synthesis.

MeSH terms

  • Acetyl-CoA C-Acyltransferase / genetics
  • Acyltransferases / genetics
  • Alcohol Oxidoreductases / genetics
  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Genes, Bacterial*
  • Genetic Complementation Test
  • Hydroxybutyrates / metabolism*
  • Molecular Sequence Data
  • Open Reading Frames
  • Polyesters / metabolism*
  • Recombinant Proteins / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Sinorhizobium meliloti / genetics*


  • Hydroxybutyrates
  • Polyesters
  • Recombinant Proteins
  • poly-beta-hydroxybutyrate
  • Alcohol Oxidoreductases
  • acetoacetyl-CoA reductase
  • Acyltransferases
  • poly-beta-hydroxybutyrate polymerase
  • Acetyl-CoA C-Acyltransferase

Associated data

  • GENBANK/U17226
  • GENBANK/U17227