Title: Biphenyl hydroxylation enhanced by an engineered o-xylene dioxygenase from Rhodococcus sp. strain DK17.

Authors: Yoo, Miyoun; Kim, Dockyu; Zylstra, Gerben J; Kang, Beom Sik; Kim, Eungbin

Published In Res Microbiol, (2011 Sep)

Abstract: Hydroxylation of the non-growth substrate biphenyl by recombinant o-xylene dioxygenases from Rhodococcus sp. strain DK17 was studied through bioconversion experiments. The metabolites from the biphenyl hydroxylation by each enzyme were identified and quantified by gas chromatography-mass spectrometry. The L266F mutant enzyme produced much more 2-hydroxybiphenyl (2.43 vs. 0.1ýýýýg/L) and 3-hydroxybiphenyl (1.97 vs. 0.03ýýýýg/L) than the wild-type. Site-directed mutagenesis combined with structural and functional analyses indicated that hydrophobic interactions and shielding effects against water are important factors in the hydroxylation of biphenyl by the o-xylene dioxygenase. The residue at position 266 plays a key role in coordinating the reaction.

PubMed ID: 21575716

MeSH Terms: Amino Acid Sequence; Bacterial Proteins/chemistry; Bacterial Proteins/genetics*; Bacterial Proteins/metabolism*; Biodegradation, Environmental; Biphenyl Compounds/chemistry; Biphenyl Compounds/metabolism*; Dioxygenases/chemistry; Dioxygenases/genetics*; Dioxygenases/metabolism*; Escherichia coli/genetics; Escherichia coli/metabolism; Gene Expression; Hydroxylation; Molecular Conformation; Molecular Sequence Data; Protein Engineering; Rhodococcus/enzymology*; Rhodococcus/genetics; Xylenes/metabolism*