Structural insights into enzymatic degradation of oxidized polyvinyl alcohol

Chembiochem. 2014 Sep 5;15(13):1882-6. doi: 10.1002/cbic.201402166. Epub 2014 Jul 8.


The ever-increasing production and use of polyvinyl alcohol (PVA) threaten our environment. Yet PVA can be assimilated by microbes in two steps: oxidation and cleavage. Here we report novel α/β-hydrolase structures of oxidized PVA hydrolase (OPH) from two known PVA-degrading organisms, Sphingopyxis sp. 113P3 and Pseudomonas sp. VM15C, including complexes with substrate analogues, acetylacetone and caprylate. The active site is covered by a lid-like β-ribbon. Unlike other esterase and amidase, OPH is unique in cleaving the CC bond of β-diketone, although it has a catalytic triad similar to that of most α/β-hydrolases. Analysis of the crystal structures suggests a double-oxyanion-hole mechanism, previously only found in thiolase cleaving β-ketoacyl-CoA. Three mutations in the lid region showed enhanced activity, with potential in industrial applications.

Keywords: beta-diketone hydrolases; catalytic triad; double oxyanion holes; environmental chemistry; hydrolases; microbial assimilation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Biocatalysis
  • Carboxylic Ester Hydrolases / chemistry*
  • Catalytic Domain
  • Gram-Negative Aerobic Bacteria / enzymology
  • Models, Molecular
  • Polyvinyl Alcohol / chemistry*
  • Pseudomonas / enzymology


  • Bacterial Proteins
  • Polyvinyl Alcohol
  • Carboxylic Ester Hydrolases
  • oxidized polyvinyl alcohol hydrolase, Pseudomonas sp.