Engineered Cytochrome P450-Catalyzed Oxidative Biaryl Coupling Reaction Provides a Scalable Entry into Arylomycin Antibiotics.

We report herein the first example of a cytochrome P450-catalyzed oxidative carbon-carbon coupling process for a scalable entry into arylomycin antibiotic cores. Starting from wild-type hydroxylating cytochrome P450 enzymes and engineered , a combination of enzyme engineering, random mutagenesis, and optimization of reaction conditions generated a P450 variant that affords the desired arylomycin core in 84% assay yield. Furthermore, this process was demonstrated as a viable route for the production of the arylomycin antibiotic core on the gram scale.

Structure of the quinoline N-hydroxylating cytochrome P450 RauA, an essential enzyme that confers antibiotic activity on aurachin alkaloids.

The cytochrome P450 RauA from Rhodococcus erythropolis JCM 6824 catalyzes the hydroxylation of a nitrogen atom in the quinolone ring of aurachin, thereby conferring strong antibiotic activity on the aurachin alkaloid. Here, we report the crystal structure of RauA in complex with its substrate, a biosynthetic intermediate of aurachin RE. Clear electron density showed that the quinolone ring is oriented parallel to the porphyrin plane of the heme cofactor, while the farnesyl chain curls into a U-shape topology and is buried inside the solvent-inaccessible hydrophobic interior of RauA.

A single mutation at the ferredoxin binding site of P450 Vdh enables efficient biocatalytic production of 25-hydroxyvitamin D(3).

Vitamin D3 hydroxylase (Vdh) from Pseudonocardia autotrophica is a cytochrome P450 monooxygenase that catalyzes the two-step hydroxylation of vitamin D3 (VD3 ) to produce 25-hydroxyvitamin D3 (25(OH)VD3 ) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2 VD3 ). These hydroxylated forms of VD3 are useful as pharmaceuticals for the treatment of conditions associated with VD3 deficiency and VD3 metabolic disorder. Herein, we describe the creation of a highly active T107A mutant of Vdh by engineering the putative ferredoxin-binding site.

Cloning and heterologous expression of the aurachin RE biosynthesis gene cluster afford a new cytochrome P450 for quinoline N-hydroxylation.

Aurachin RE is a prenylated quinoline antibiotic that was first isolated from the genus Rhodococcus. It shows potent antibacterial activity against a variety of Gram-positive bacteria. Here we have identified a minimal biosynthesis gene cluster for aurachin RE in Rhodococcus erythropolis JCM 6824 by using random transposon mutagenesis and heterologous production.

Total cellular glycomics allows characterizing cells and streamlining the discovery process for cellular biomarkers.

Although many of the frequently used pluripotency biomarkers are glycoconjugates, a glycoconjugate-based exploration of novel cellular biomarkers has proven difficult due to technical difficulties. This study reports a unique approach for the systematic overview of all major classes of oligosaccharides in the cellular glycome. The proposed method enabled mass spectrometry-based structurally intensive analyses, both qualitatively and quantitatively, of cellular N- and O-linked glycans derived from glycoproteins, glycosaminoglycans, and glycosphingolipids, as well as free oligosaccharides of human embryonic stem cells (hESCs), induced pluripotent stem cells (hiPSCs), and various human cells derived from normal and carcinoma cells.

Structure-guided mutagenesis for the improvement of substrate specificity of Bacillus megaterium glucose 1-dehydrogenase IV.

Bacillus megaterium IAM 1030 (Bacillus sp. JCM 20016) possesses four d-glucose 1-dehydrogenase isozymes (BmGlcDH-I, -II, -III and -IV) that belong to the short-chain dehydrogenase/reductase superfamily. The BmGlcDHs are currently used for a clinical assay to examine blood glucose levels.

The proteasomal subunit Rpn6 is a molecular clamp holding the core and regulatory subcomplexes together.

Proteasomes execute the degradation of most cellular proteins. Although the 20S core particle (CP) has been studied in great detail, the structure of the 19S regulatory particle (RP), which prepares ubiquitylated substrates for degradation, has remained elusive. Here, we report the crystal structure of one of the RP subunits, Rpn6, and we describe its integration into the cryo-EM density map of the 26S holocomplex at 9.

Permeabilization induced by lipid II-targeting lantibiotic nisin and its effect on the bioconversion of vitamin D3 to 25-hydroxyvitamin D3 by Rhodococcus erythropolis.

Vitamin D3 (VD3) is a fat-soluble prohormone in mammals. VD3 is inert and must be activated by hydroxylation at the C-25 and C-1α positions to exert its biological activity. We recently accomplished the bioconversion of VD3 to 25(OH)VD3 with a recombinant strain of Rhodococcus erythropolis and found that the permeability of VD3 into the cytoplasm may be the rate-limiting step of 25(OH)VD3 production (Sallam et al.

Structural evidence for enhancement of sequential vitamin D3 hydroxylation activities by directed evolution of cytochrome P450 vitamin D3 hydroxylase.

Vitamin D(3) hydroxylase (Vdh) isolated from actinomycete Pseudonocardia autotrophica is a cytochrome P450 (CYP) responsible for the biocatalytic conversion of vitamin D(3) (VD(3)) to 1α,25-dihydroxyvitamin D(3) (1α,25(OH)(2)VD(3)) by P. autotrophica. Although its biological function is unclear, Vdh is capable of catalyzing the two-step hydroxylation of VD(3), i.

Biosynthetic gene-based secondary metabolite screening: a new diterpene, methyl phomopsenonate, from the fungus Phomopsis amygdali.

The presence of the geranylgeranyl diphosphate synthase (GGS) gene is a common feature of gene clusters for diterpene biosynthesis. We demonstrated identification of a diterpene gene cluster using homology-based PCR of GGS genes and the subsequent genome walking in the fungus Phomopsis amygdali N2. Structure determination of a novel diterpene hydrocarbon phomopsene provided by enzymatic synthesis with the recombinant terpene synthase PaPS and screening of fungal broth extracts with reference to characteristic NMR signals of phomopsene allowed us to isolate a new diterpene, methyl phomopsenonate.

C-terminal tail derived from the neighboring subunit is critical for the activity of Thermoplasma acidophilum D-aldohexose dehydrogenase.

The D-aldohexose dehydrogenase from the thermoacidophilic archaeon Thermoplasma acidophilum (AldT) is a homotetrameric enzyme that catalyzes the oxidation of several D-aldohexoses, especially D-mannose. AldT comprises a unique C-terminal tail motif (residues 247-255) that shuts the active-site pocket of the neighboring subunit. The functional role of the C-terminal tail of AldT has been investigated using mutational and crystallographic analyses.