as a Transient Expression Host to Produce Auxin Analogs.

Plant secondary metabolites have applications for the food, biofuel, and pharmaceutical industries. Recent advances in pathway elucidation and host expression systems now allow metabolic engineering of plant metabolic pathways to produce "new-to-nature" derivatives with novel biological activities, thereby amplifying the range of industrial uses for plant metabolites. Here we use a transient expression system in the model plant to reconstitute the two-step plant-derived biosynthetic pathway for auxin (indole acetic acid) to achieve accumulation up to 500 ng/g fresh mass (FM).

Structure and Biocatalytic Scope of Coclaurine N-Methyltransferase.

Benzylisoquinoline alkaloids (BIAs) are a structurally diverse family of plant secondary metabolites, which have been exploited to develop analgesics, antibiotics, antitumor agents, and other therapeutic agents. Biosynthesis of BIAs proceeds via a common pathway from tyrosine to (S)-reticulene at which point the pathway diverges. Coclaurine N-methyltransferase (CNMT) is a key enzyme in the pathway to (S)-reticulene, installing the N-methyl substituent that is essential for the bioactivity of many BIAs.

An Unusual Flavin-Dependent Halogenase from the Metagenome of the Marine Sponge Theonella swinhoei WA.

Uncultured bacteria from sponges have been demonstrated to be responsible for the generation of many potent, bioactive natural products including halogenated metabolites.1 The identification of gene clusters from the metagenomes of such bacterial communities enables the discovery of enzymes that mediate new and useful chemistries and allows insight to be gained into the biogenesis of potentially pharmacologically important natural products. Here we report a new pathway to the keramamides (krm); the first functional evidence for the existence of a distinct producer in the Theonella swinhoei WA chemotype is revealed, and a key enzyme on the pathway, a unique flavin-dependent halogenase with a broad substrate specificity, with potential as a useful new biocatalytic tool, is described.

Promiscuous indolyl vinyl isonitrile synthases in the biogenesis and diversification of hapalindole-type alkaloids.

The hapalindole-type alkaloids naturally show striking late stage diversification of what was believed to be a conserved intermediate, -indolyl vinyl isonitrile (). Here we demonstrate enzymatically, as well as through applying a synthetic biology approach, that the pathway generating (itself, a potent natural broad-spectrum antibiotic) is also dramatically flexible. We harness this to enable early stage diversification of the natural product and generation of a wide range of halo-analogues of .

The first one-pot synthesis of L-7-iodotryptophan from 7-iodoindole and serine, and an improved synthesis of other L-7-halotryptophans.

A simple and scalable one-pot biotransformation enables direct access to L-halotryptophans, including L-7-iodotryptophan, from the corresponding haloindoles. The biotransformation utilizes an easy to prepare bacterial cell lysate that may be stored as the lyophilizate for several months and utilized as a catalyst as and when required.

Scope and potential of halogenases in biosynthetic applications.

A large and diverse series of halogenated natural products exist. In many of these compounds the halogen is important to biological activity and bioavailability. We now recognise that nature has developed many different halogenation strategies for which well-known enzyme classes such as haem oxidases or flavin-dependent oxidases have been adapted.