The Pva Operon Is Located on the Megaplasmid of Sphingopyxis Sp. Strain 113P3 and Is Constitutively Expressed, Although Expression Is Enhanced by PVA

Appl Microbiol Biotechnol. 2008 Mar;78(4):685-93. doi: 10.1007/s00253-008-1348-y. Epub 2008 Jan 24.


The upstream and downstream regions of the tentative pva operon including genes encoding oxidized polyvinyl alcohol (PVA) hydrolase (oph), PVA dehydrogenase (pvaA) and cytochrome c (cytC) from Sphingopyxis sp. strain 113P3 were sequenced. The resultant 7.9 kb sequence contained orf1 in the upstream region and orf2 and orf3 in the downstream region. Reverse transcription-polymerase chain reaction (PCR) analyses revealed that the intergenic regions between orf1 and oph or between cytC and orf2 were expressed neither in PVA medium nor glucose medium, indicating that the pva operon consists of three genes. A transcription start site was determined by 5'-rapid amplification of cDNA ends to be 428 bp upstream of the start codon of the oph. The stop codon of cytC was followed by a sequence of inverted repeats that could function as a factor-independent transcription terminator. Strain 113P3 had one megaplasmid including the pva operon. Northern blot hybridization for the three genes revealed that mRNA size was approximately 3 to 4 kb and expression was elevated in PVA medium compared to glucose medium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / genetics*
  • Alcohol Oxidoreductases / metabolism
  • Base Sequence
  • Cloning, Molecular
  • Cytochromes c / genetics
  • Cytochromes c / metabolism
  • DNA, Bacterial / analysis
  • DNA, Bacterial / genetics
  • Molecular Sequence Data
  • Operon*
  • Plasmids / analysis
  • Plasmids / genetics*
  • Plasmids / isolation & purification
  • Polyvinyl Alcohol / metabolism*
  • Sequence Analysis, DNA
  • Sphingomonadaceae / enzymology*
  • Sphingomonadaceae / genetics
  • Transcription, Genetic


  • DNA, Bacterial
  • Polyvinyl Alcohol
  • Cytochromes c
  • Alcohol Oxidoreductases
  • polyvinyl-alcohol dehydrogenase (acceptor)