Identification of a critical gene involved in the biosynthesis of the polyene macrolide lavencidin in FRI-5 using the Target-AID (activation-induced cytidine deaminase) base editing technology.

Polyene macrolide antibiotics, produced mainly as secondary metabolites of streptomycetes, have distinct chemical structures and include clinically important antifungal drugs. We recently isolated the 28-membered polyene macrolide lavencidin from FRI-5. Here, we identify and characterize the lavencidin biosynthetic () gene cluster by combining a gene disruption system based on a base editing technology and analysis.

Validation of machine learning-assisted screening of PKC ligands: PKC binding affinity and activation.

Protein kinase C (PKC) is a family of serine/threonine kinases, and PKC ligands have the potential to be therapeutic seeds for cancer, Alzheimer's disease, and human immunodeficiency virus infection. However, in addition to desired therapeutic effects, most PKC ligands also exhibit undesirable pro-inflammatory effects. The discovery of new scaffolds for PKC ligands is important for developing less inflammatory PKC ligands, such as bryostatins.

Activation of cryptic milbemycin A production in Streptomyces sp. BB47 by the introduction of a functional bldA gene.

Streptomycetes are characterized by their ability to produce structurally diverse compounds as secondary metabolites and by their complex developmental life cycle, which includes aerial mycelium formation and sporulation. The production of secondary metabolites is growth-stage dependent, and generally coincides with morphological development on a solid culture. Streptomyces sp.

Heterologous gene expression and characterization of two serine hydroxymethyltransferases from Thermoplasma acidophilum.

Serine hydroxymethyltransferase (SHMT) and threonine aldolase are classified as fold type I pyridoxal-5'-phosphate-dependent enzymes and engaged in glycine biosynthesis from serine and threonine, respectively. The acidothermophilic archaeon Thermoplasma acidophilum possesses two distinct SHMT genes, while there is no gene encoding threonine aldolase in its genome. In the present study, the two SHMT genes (Ta0811 and Ta1509) were heterologously expressed in Escherichia coli and Thermococcus kodakarensis, respectively, and biochemical properties of their products were investigated.

Germination stimulatory activity of bacterial butenolide hormones from J1074 on seeds of the root parasitic weed .

Damage caused by Orobanchaceae root parasitic weeds is a substantial agricultural problem for global food security. Many studies have been conducted to establish practical methods of control, but efforts are still required for successful management. Seed germination of root parasitic weeds requires host-derived germination stimulants including strigolactones (SLs).

Production of Coenzyme A Using Thermophilic Enzymes.

Coenzyme A (CoA) is an essential cofactor present in all domains of life and is involved in numerous metabolic pathways, including fatty acid metabolism, pyruvate oxidation through the tricarboxylic acid (TCA) cycle, and the production of secondary metabolites. This characteristic makes CoA a commercially valuable compound in the pharmaceutical, cosmetic, and clinical industries. However, CoA is difficult to accumulate in living cells at a high level, since it is consumed in multiple metabolic pathways, hampering its manufacturing by typical cell cultivation and extraction approaches.

Lavencidin, a polyene macrolide antibiotic from Streptomyces lavendulae FRI-5.

In our screening program for new biologically active compounds, a new polyene macrolide, lavencidin (1), along with known compound RKGS-A2215A (2), was isolated from the fermentation broth of Streptomyces lavendulae FRI-5 by changing the composition of liquid medium normally used for the strain. Their structures were elucidated by spectral methods (high-resolution fast-atom bombardment mass spectrometry (HRFABMS) and nuclear magnetic resonance (NMR)). Compound 1 includes a conjugated pentaene moiety together with six hydroxy groups and a carboxylic acid as a side chain.

Identification of biosynthetic genes for the β-carboline alkaloid kitasetaline and production of the fluorinated derivatives by heterologous expression.

β-Carboline alkaloids exhibit a broad spectrum of pharmacological and biological activities and are widely distributed in nature. Genetic information on the biosynthetic mechanism of β-carboline alkaloids has not been accumulated in bacteria, because there are only a few reports on the microbial β-carboline compounds. We previously isolated kitasetaline, a mercapturic acid derivative of a β-carboline compound, from the genetically modified Kitasatospora setae strain and found a plausible biosynthetic gene cluster for kitasetaline.

Engineered production of kitasetalic acid, a new tetrahydro-β-carboline with the ability to suppress glucose-regulated protein synthesis.

β-Carboline alkaloids and related compounds show a broad spectrum of biological activities. We previously identified new members of the β-carboline alkaloid family by using an engineered Kitasatospora setae strain and a heterologous Streptomyces host expressing the plausible biosynthetic genes, including the hypothetical gene kse_70640 (kslB). Here, we elucidated the chemical structure of a new tetrahydro-β-carboline compound (named kitasetalic acid) that appeared in a heterologous Streptomyces host expressing the kslB gene alone.

Cystargamide B, a cyclic lipodepsipeptide with protease inhibitory activity from Streptomyces sp.

We identified a new cyclic lipodepsipeptide, cystargamide B (1), from the mycelial extract of a Kaempferia galanga rhizome-derived actinomycete strain, Streptomyces sp. PB013. The planar structure was elucidated based on high resolution fast-atom bombardment mass spectrometry (HRFABMS) spectroscopy and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopic data.

Butenolides from Streptomyces albus J1074 Act as External Signals To Stimulate Avermectin Production in Streptomyces avermitilis.

In streptomycetes, autoregulators are important signaling compounds that trigger secondary metabolism, and they are regarded as hormones based on their extremely low effective concentrations (nM) and the involvement of specific receptor proteins. Our previous distribution study revealed that butenolide-type hormones, including avenolide, are a general class of signaling molecules in streptomycetes and that strain J1074 may produce butenolide-type hormones. Here, we describe metabolite profiling of a disruptant of the gene, which encodes a key biosynthetic enzyme for butenolide-type hormones, and identify four butenolide compounds from J1074 that show avenolide activity.

Corrigendum: Total synthesis and absolute configuration of avenolide, extracellular factor in Streptomyces avermitilis.

This corrects the article DOI: 10.1038/ja.2011.

Characterization of the biosynthetic gene cluster for cryptic phthoxazolin A in Streptomyces avermitilis.

Phthoxazolin A, an oxazole-containing polyketide, has a broad spectrum of anti-oomycete activity and herbicidal activity. We recently identified phthoxazolin A as a cryptic metabolite of Streptomyces avermitilis that produces the important anthelmintic agent avermectin. Even though genome data of S.

Discovery of a new diol-containing polyketide by heterologous expression of a silent biosynthetic gene cluster from Streptomyces lavendulae FRI-5.

The genome of streptomycetes has the ability to produce many novel and potentially useful bioactive compounds, but most of which are not produced under standard laboratory cultivation conditions and are referred to as silent/cryptic secondary metabolites. Streptomyces lavendulae FRI-5 produces several types of bioactive compounds. However, this strain may also have the potential to biosynthesize more useful secondary metabolites.

Discovering potential Streptomyces hormone producers by using disruptants of essential biosynthetic genes as indicator strains.

Autoregulators are low-molecular-weight signaling compounds that control the production of many secondary metabolites in actinomycetes and have been referred to as 'Streptomyces hormones'. Here, potential producers of Streptomyces hormones were investigated in 40 Streptomyces and 11 endophytic actinomycetes. Production of γ-butyrolactone-type (IM-2, VB) and butenolide-type (avenolide) Streptomyces hormones was screened using Streptomyces lavendulae FRI-5 (ΔfarX), Streptomyces virginiae (ΔbarX) and Streptomyces avermitilis (Δaco), respectively.

Rakicidin F, a new antibacterial cyclic depsipeptide from a marine sponge-derived Streptomyces sp.

A new cyclic depsipeptide, rakicidin F (1), along with the known compound rakicidin C (2), was isolated from the fermentation broth of the marine sponge-derived actinomycete strain Streptomyces sp. GKU 220. Their structures were elucidated by interpreting the HRFABMS and NMR spectroscopic data.

Activation of cryptic phthoxazolin A production in Streptomyces avermitilis by the disruption of autoregulator-receptor homologue AvaR3.

The genomes of actinomycetes encode many cryptic novel/useful bioactive compounds, but access to these cryptic secondary metabolites remains limited. Streptomyces avermitilis predominantly produces three polyketide antibiotics (avermectin, filipin, and oligomycin) but has the potential to produce more secondary metabolites based on the number of cryptic biosynthetic gene clusters. Here, we extensively investigated the metabolite profiles of a gene disruptant of AvaR3 (an autoregulator receptor homologue), which is involved in the pleiotropic regulation of antibiotic production and cell morphology.

Identification and characterization of lbpA, an indigoidine biosynthetic gene in the γ-butyrolactone signaling system of Streptomyces lavendulae FRI-5.

Streptomyces lavendulae FRI-5 produces the blue pigment indigoidine and other secondary metabolites (d-cycloserine and nucleoside antibiotics). The production of these useful compounds is controlled by a signaling cascade mediated by the γ-butyrolactone autoregulator IM-2. Previously we revealed that the far regulatory island includes the IM-2 receptor, the IM-2 biosynthetic enzyme, and several transcriptional regulators, and that it contributes to the regulation of indigoidine production in response to the signaling molecule.

Characterization of AvaR1, a butenolide-autoregulator receptor for biosynthesis of a Streptomyces hormone in Streptomyces avermitilis.

Streptomyces hormones, sometimes called as autoregulators, are important signaling molecules to trigger secondary metabolism across many Streptomyces species. We recently identified a butenolide-type autoregulator (termed avenolide) as a new class of Streptomyces hormone from Streptomyces avermitilis that produces important anthelmintic agent avermectin. Avenolide triggers the production of avermectin with minimum effective concentration of nanomolar.

Characterization of the biosynthetic gene cluster for maklamicin, a spirotetronate-class antibiotic of the endophytic Micromonospora sp. NBRC 110955.

Maklamicin, which is produced by the endophytic Micromonospora sp. NBRC 110955, is a spirotetronate-class antibiotic possessing anti-microbial activity against Gram-positive bacteria, and has several unique structural features different from other spirotetronates. Here we describe identification and characterization of the maklamicin biosynthetic (mak) gene cluster through draft genome sequencing, genomic library screening, and gene disruption.

Regulation of production of the blue pigment indigoidine by the pseudo γ-butyrolactone receptor FarR2 in Streptomyces lavendulae FRI-5.

The γ-butyrolactone autoregulator signaling cascade is widely distributed among Streptomyces species as an important regulatory system of secondary metabolism. In Streptomyces lavendulae FRI-5, a γ-butyrolactone autoregulator IM-2 and the IM-2 specific receptor FarA control production of the blue pigment indigoidine together with two types of antibiotics: d-cycloserine and the nucleoside antibiotics. Here, we demonstrated by in silico analysis that farR2 (a farA homologue), which is located in a cluster of regulatory genes including farA, belongs to the family of pseudoreceptor regulator genes, and that the expression of farR2 is controlled by the IM-2/FarA regulatory system.

29-Deoxymaklamicin, a new maklamicin analogue produced by a genetically engineered strain of Micromonospora sp. NBRC 110955.

Maklamicin is a spirotetronate-class antibiotic produced by Micromonospora sp. NBRC 110955, and a polyketide assembly line and a glycerate utilization system are involved in its biosynthesis. One tailoring step in the biosynthesis is predicted to be post-polyketide synthase (PKS) modification, which seems to be catalysed by putative cytochrome P450 monooxygenases, MakC2 and/or MakC3.

Differential contributions of two SARP family regulatory genes to indigoidine biosynthesis in Streptomyces lavendulae FRI-5.

The Streptomyces antibiotic regulatory protein (SARP) family regulators have been shown to control the production of secondary metabolites in many Streptomyces species as the most downstream regulators in the regulatory cascade. Streptomyces lavendulae FRI-5 produces a blue pigment (indigoidine) together with two types of antibiotics: D-cycloserine and the nucleoside antibiotics. The production of these secondary metabolites is governed by a signaling system consisting of a γ-butyrolactone, IM-2 [(2R,3R,1'R)-2-1'-hydroxybutyl-3-hydroxymethyl-γ-butanolide], and its cognate receptor, FarA.