Cloning and heterologous expression of P450Um-1, a novel bacterial P450 gene, for hydroxylation of immunosuppressive agent AS1387392

Cloning and heterologous expression of P450Lent4B11, a novel bacterial P450 gene, for hydroxylation of an antifungal agent sordaricin

Microbial transformation is known to be one of promising options to add functional groups such as a hydroxyl moiety to active base compounds to generate their derivatives. Sordaricin, a diterpene aglycone of the natural product sordarin, is an antifungal agent to selectively inhibit fungal protein synthesis by stabilizing the ribosome/EF-2 (elongation factor 2) complex. We screened actinomycetes to catalyze hydroxylation of sordaricin on the basis that the hydroxyl moiety would make it easier to generate derivatives of sordaricin. As a result of the screening, 6-hydroxylation of sordaricin was found to be catalyzed by Lentzea sp. 7887. We found that the cytochrome P450 inhibitor metyrapone inhibited this reaction, suggesting that a cytochrome P450 may be responsible for the biotransformation. As a next step, we cloned multiple cytochrome P450 genes, one of which were named P450Lent4B11, using degenerate PCR primers. The expressed cytochrome P450 derived from the P450Lent4B11 gene provided a different absorbance spectrum pattern from original one when it was incubated with sordaricin. Moreover, in cell-free conditions, the corresponding cytochrome P450 displayed the 6-hydroxylation activity toward sordaricin. Taken together, these results indicate that P450Lent4B11, derived from Lentzea sp. 7887, should be responsible for catalyzing 6-hydroxylation of sordaricin.

Complete genome sequence of Streptomyces lividans TK24

Streptomyces lividans TK24 is the standard host for the heterologous expression of a number of different proteins and antibiotic-synthesizing enzymes. As such, it is often used as an experimental microbial cell factory for the production of secreted heterologous proteins including human cytokines and industrial enzymes, and of several antibiotics. It accepts methylated DNA and is an ideal Streptomyces cloning system. Here, we report the complete genome sequence of S. lividans TK24 that includes a plasmid-less genome of 8.345Mbp (72.24% G+C content).

Characterization of a novel cytochrome P450 from Amycolatopsis sp. CGMCC1149 for hydroxylation of lovastatin

Wuxistatin, a novel and potent statin, is converted from lovastatin by Amycolatopsis sp. CGMCC1149. In the bioconversion, lovastatin is firstly hydroxylated to 3-hydroxymethyl lovastatin (product I) by a hydroxylase. In the current study, a novel hydroxylase gene p450lov was isolated from Amycolatopsis sp. CGMCC1149 by degenerate PCR and self-formed adaptor PCR and expressed in Escherichia coli. The gene encodes a 403-amino-acid protein with a molecular weight of 44.8 kDa and was designated as a new member of cytochrome P450 (CYP) 105 family, CYP105A44. Meanwhile, a lovastatin catalytic in vitro system was established, and an optimal hydroxylation reaction system contained 30 µM lovastatin, 600 µM NADH, 120 µM ferredoxin, 0.04 U ferredoxin-nicotinamide adenine dinucleotide phosphate reductase, and 100 µM CYP105A44 in a final volume of 200 µL Tris HCl buffer (50 mM, pH 7.4). These would be helpful for further studies on the hydroxylation of statins.