Characterization of a cytochrome P450 monooxygenase capable of high molecular weight PAHs oxidization from Rhodococcus sp. P14

•PAHs can induce the transcription of gene cyp108j1.•CYP108J1 initialize PAHs oxidization only with its own electron transport system.•Metabolites were detected by using CYP108J1 on the treatment of different PAHs.

Rhodococcus sp. P14 is able to degrade a wide range of polycyclic aromatic hydrocarbons (PAHs). By analyzing its whole genome sequence, a gene cluster encoding cytochrome P450 monooxygenase (CYP108J1) with ferredoxin (fdx) and ferredoxin reductase (hcaD) relating to polycyclic aromatic hydrocarbons degradation was predicted. Protein sequence analysis of CYP108J1 showed 47.9% and 36.4% identity to the CYP108A1 and CYP108D1 from Pseudomonas sp. and N. aromaticivorans DSM12444 in CYP108 family, respectively. The transcriptional level of gene cyp108j1 was up-regulated when the strain was grown within the medium containing benz[a]anthracene, pyrene, phenanthrene and anthracene as the sole carbon source, and the increment was detected to be 2.4, 8.0, 16.0 and 11.3-fold, respectively, by comparing to that grown with glucose. Further investigation on the recombinant protein CYP108J1 in E. coli also indicates that CYP108J1 was capable of degrading a series of PAHs compounds (from low to high molecular weight), including biphenyl, phenanthrene, anthracene and benz[a]anthracene.

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