Structural insights into enzymatic degradation of oxidized polyvinyl alcohol
Yang, Y., Ko, T.P., Liu, L., Li, J., Huang, C.H., Chan, H.C., Ren, F., Jia, D., Wang, A.H.-J., Guo, R.T., Chen, J., Du, G.(2014) Chembiochem 15: 1882-1886
- PubMed: 25044912 
- DOI: https://doi.org/10.1002/cbic.201402166
- Primary Citation of Related Structures:  
3WL5, 3WL6, 3WL7, 3WL8, 3WLA - PubMed Abstract: 
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 CC 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.
Organizational Affiliation: 
Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Lihu Ave. 1800, Wuxi 214122 (China).