Genome-Led Discovery of the Antibacterial Cyclic Lipopeptide Kutzneridine A and Its Silent Biosynthetic Gene Cluster from Species.

Genome analysis of sp. CA-103260 revealed a putative lipopeptide-encoding biosynthetic gene cluster (BGC) that was cloned into a bacterial artificial chromosome (BAC) and heterologously expressed in M1152. As a result, a novel cyclic lipo-tetrapeptide containing two diaminopropionic acid residues and an exotic ,-acetonide ring, kutzneridine A (), was isolated and structurally characterized.

Maramycin, a Cytotoxic Isoquinolinequinone Terpenoid Produced through Heterologous Expression of a Bifunctional Indole Prenyltransferase/Tryptophan Indole-Lyase in .

Isoquinolinequinones represent an important family of natural alkaloids with profound biological activities. Heterologous expression of a rare bifunctional indole prenyltransferase/tryptophan indole-lyase enzyme from P8-A2 in J1074 led to the activation of a putative isoquinolinequinone biosynthetic gene cluster and production of a novel isoquinolinequinone alkaloid, named maramycin (). The structure of maramycin was determined by analysis of spectroscopic (1D/2D NMR) and MS spectrometric data.

Biosynthesis of the Azoxy Compound Azodyrecin from P8-A2.

Azoxy compounds are a distinctive group of bioactive secondary metabolites characterized by a unique RN═N(O)R moiety. The azoxy moiety is present in various classes of metabolites that exhibit various biological activities. The enzymatic mechanisms underlying azoxy bond formation remain enigmatic.

Systems Analysis of Highly Multiplexed CRISPR-Base Editing in Streptomycetes.

CRISPR tools, especially Cas9n-sgRNA guided cytidine deaminase base editors such as CRISPR-BEST, have dramatically simplified genetic manipulation of streptomycetes. One major advantage of CRISPR base editing technology is the possibility to multiplex experiments in genomically instable species. Here, we demonstrate scaled up Csy4 based multiplexed genome editing using CRISPR-mcBEST in .

Properties of Multidrug-Resistant Mutants Derived from Heterologous Expression Chassis Strain J1074.

J1074 is a popular platform to discover novel natural products via the expression of heterologous biosynthetic gene clusters (BGCs). There is keen interest in improving the ability of this platform to overexpress BGCs and, consequently, enable the purification of specialized metabolites. Mutations within gene for the β-subunit of RNA polymerase are known to increase rifampicin resistance and augment the metabolic capabilities of streptomycetes.