MOESM1 of Identification and utilization of two important transporters: SgvT1 and SgvT2, for griseoviridin and viridogrisein biosynthesis in Streptomyces griseoviridis

Additional file 1: Figure S1. The multiple alignment of SgvT1/T3 with other transporters. Figure S2. The multiple alignment of SgvT2 with other transporters. Figures S3–S5. The inactivation of sgvT1-T3. Figure S6–S8. HPLC analyses of the fermentation extract of Wild-type & ΔsgvT1-T3. Figure S9. HPLC analyses of the fermentation extract of WT::sgvT1–T2. Figure S10. The HPLC standard curve of GV/ VG. Figure S11. HPLC analyses of fermentation extract of complemented mutants. Table S1. Primer pairs used for PCR-targeting of sgvT1–T3. Table S2. Primers used for PCR confirmation of double-crossover mutants. Table S3. Primer pairs used for complementation of sgvT1–T3. Table S4. Primer pairs used for RT-PCR. Table S5. Primer pairs used for qPCR. Table S6. Quantitative analysis of GV/VG production

Discovery of a New Family of Dieckmann Cyclases Essential to Tetramic Acid and Pyridone-Based Natural Products Biosynthesis

Bioinformatic analyses indicate that TrdC, SlgL, LipX₂, KirHI, and FacHI belong to a group of highly homologous proteins involved in biosynthesis of actinomycete-derived tirandamycin B, streptolydigin, α-lipomycin, kirromycin, and factumycin, respectively. However, assignment of their biosynthetic roles has remained elusive. Gene inactivation and complementation, <i>in vitro</i> biochemical assays with synthetic analogues, point mutations, and phylogenetic tree analyses reveal that these proteins represent a new family of Dieckmann cyclases that drive tetramic acid and pyridone scaffold biosynthesis

Base-Mediated Cascade Substitution–Cyclization of 2<i>H</i>‑Azirines: Access to Highly Substituted Oxazoles

A novel strategy to synthesize highly functionalized oxazoles has been successfully developed via a base-mediated intermolecular substitution between 2-acyloxy-2<i>H</i>-azirines and <i>N</i>-nucleophile or <i>O</i>-nucleophile with a subsequent ring expansion of a 2<i>H</i>-azirine intermediate. This method provides straightforward access to highly substituted oxazoles with high efficiency and excellent functional group compatibility under metal-free reaction conditions

Enzymatic Synthesis of GDP-α‑l‑fucofuranose by MtdL and Hyg20

Two mutases, MtdL and Hyg20, are reported. Both are able to functionally drive the biosynthesis of GDP-α-l-fucofuranose. Both enzymes catalyze similar functions, catalytically enabling the bidirectional reaction between GDP-β-l-fucopyranose and GDP-α-l-fucofuranose using only divalent cations as cofactors. This realization is but one of a number of important insights into fucofuranose biosynthesis presented herein

Biosynthesis of 9‑Methylstreptimidone Involves a New Decarboxylative Step for Polyketide Terminal Diene Formation

9-Methylstreptimidone is a glutarimide antibiotic showing antiviral, antifungal, and antitumor activities. Genome scanning, bioinformatics analysis, and gene inactivation experiments reveal a gene cluster responsible for the biosynthesis of 9-methylstreptimidone in <i>Streptomyces himastatinicus</i>. The unveiled machinery features both acyltransferase- and thioesterase-less iterative use of module 5 as well as a branching module for glutarimide generation. Impressively, inactivation of <i>smdK</i> leads to a new carboxylate analogue unveiling a new mechanism for polyketide terminal diene formation

flea unigenes, ORFs, and functional annotations

flea unigenes, ORFs, and functional annotation

Identification of the Grincamycin Gene Cluster Unveils Divergent Roles for GcnQ in Different Hosts, Tailoring the l‑Rhodinose Moiety

The gene cluster responsible for grincamycin (GCN, <b>1</b>) biosynthesis in <i>Streptomyces lusitanus</i> SCSIO LR32 was identified; heterologous expression of the GCN cluster in <i>S. coelicolor</i> M512 yielded P-1894B (<b>1b</b>) as a predominant product. The <i>ΔgcnQ</i> mutant accumulates intermediate <b>1a</b> and two shunt products <b>2a</b> and <b>3a</b> bearing l-rhodinose for l-cinerulose A substitutions. In vitro data demonstrated that GcnQ is capable of iteratively tailoring the two l-rhodinose moieties into l-aculose moieties, supporting divergent roles of GcnQ in different hosts

Δ^11,12 Double Bond Formation in Tirandamycin Biosynthesis is Atypically Catalyzed by TrdE, a Glycoside Hydrolase Family Enzyme

The tirandamycins (TAMs) are a small group of Streptomyces-derived natural products that target bacterial RNA polymerase. Within the TAM biosynthetic cluster, <i>trdE</i> encodes a glycoside hydrolase whose role in TAM biosynthesis has been undefined until now. We report that in vivo <i>trdE</i> inactivation leads to accumulation of pre-tirandamycin, the earliest intermediate released from its mixed polyketide/nonribosomal peptide biosynthetic assembly line. In vitro and site-directed mutagenesis studies showed that TrdE, a putative glycoside hydrolase, catalyzes in a highly atypical fashion the installation of the Δ^11,12 double bond during TAM biosynthesis

Cytotoxic Angucycline Class Glycosides from the Deep Sea Actinomycete <i>Streptomyces lusitanus</i> SCSIO LR32

Five new <i>C</i>-glycoside angucyclines, named grincamycins B–F (<b>1</b>–<b>5</b>), and a known angucycline antibiotic, grincamycin (<b>6</b>), were isolated from <i>Streptomyces lusitanus</i> SCSIO LR32, an actinomycete of deep sea origin. The structures of these compounds were elucidated on the basis of extensive spectroscopic analyses, including MS and 1D and 2D NMR experiments. All compounds except grincamycin F (<b>5</b>) exhibited <i>in vitro</i> cytotoxicities against the human cancer cell lines HepG2, SW-1990, HeLa, NCI-H460, and MCF-7 and the mouse melanoma cell line B16, with IC₅₀ values ranging from 1.1 to 31 μM

MLVA Genotyping of <i>Brucella melitensis and Brucella abortus</i> Isolates from Different Animal Species and Humans and Identification of <i>Brucella suis</i> Vaccine Strain S2 from Cattle in China

<div><p>In China, brucellosis is an endemic disease and the main sources of brucellosis in animals and humans are infected sheep, cattle and swine. <i>Brucella melitensis</i> (biovars 1 and 3) is the predominant species, associated with sporadic cases and outbreak in humans. Isolates of <i>B. abortus</i>, primarily biovars 1 and 3, and <i>B. suis</i> biovars 1 and 3 are also associated with sporadic human brucellosis. In this study, the genetic profiles of <i>B. melitensis</i> and <i>B. abortus</i> isolates from humans and animals were analyzed and compared by multi-locus variable-number tandem-repeat analysis (MLVA). Among the <i>B. melitensis</i> isolates, the majority (74/82) belonged to MLVA8 genotype 42, clustering in the ‘East Mediterranean’ group. Two <i>B. melitensis</i> biovar 1 genotype 47 isolates, belonging to the ‘Americas’ group, were recovered; both were from the Himalayan blue sheep (<i>Pseudois nayaur</i>, a wild animal). The majority of <i>B. abortus</i> isolates (51/70) were biovar 3, genotype 36. Ten <i>B. suis</i> biovar 1 field isolates, including seven outbreak isolates recovered from a cattle farm in Inner Mongolia, were genetically indistinguishable from the vaccine strain S2, based on MLVA cluster analysis. MLVA analysis provided important information for epidemiological trace-back. To the best of our knowledge, this is the first report to associate <i>Brucella</i> cross-infection with the vaccine strain S2 based on molecular comparison of recovered isolates to the vaccine strain. MLVA typing could be an essential assay to improve brucellosis surveillance and control programs.</p> </div