Aetokthonotoxin (AETX) is a cyanobacterial neurotoxin that causes vacuolar myelinopathy, neurological disease particularly deadly to bald eagles in the United States. The recently characterized AETX structurally unique among cyanotoxins and composed of pentabrominated biindole nitrile. Herein we report discovery an efficient, five-enzyme biosynthetic pathway freshwater cyanobacterium

The biosynthetic installation of halogen atoms is largely performed by oxidative halogenases that target a wide array electron-rich substrates, including aromatic compounds and conjugated systems. Halogenated alkyne-containing molecules are known to occur in Nature; however, atom on the terminus an alkyne has not been demonstrated enzyme catalysis. Herein, we report discovery characterization alkynyl halogenase natural product biosynthesis. We show flavin-dependent from jamaicamide pathway,...

The remarkable degree of synthetic selectivity found in Nature is exemplified by the biosynthesis paralytic shellfish toxins such as saxitoxin. polycyclic core shared saxitoxin and its relatives assembled subsequently elaborated through installation hydroxyl groups with exquisite precision that not possible to replicate traditional methods. Here, we report identification enzymes carry out a subset C-H functionalizations involved toxin biosynthesis. We have shown three Rieske oxygenases...

Biocatalysts that perform C-H hydroxylation exhibit exceptional substrate specificity and site-selectivity, often through the use of high valent oxidants to activate these inert bonds. Rieske oxygenases are examples enzymes with ability precise mono- or dioxygenation reactions on a variety substrates. Understanding structural features responsible for control over selectivity is essential enable development this class biocatalytic applications. Decades research has illuminated critical common...

Small molecules that bind to voltage-gated sodium channels (VGSCs) are promising leads in the treatment of numerous neurodegenerative diseases and pain. Nature is a highly skilled medicinal chemist this regard, designing potent VGSC ligands capable binding blocking channel, thereby offering compounds potential therapeutic interest. Paralytic shellfish toxins (PSTs), produced by cyanobacteria marine dinoflagellates, examples these naturally occurring small molecule blockers can potentially be...

Abstract Rieske oxygenases exploit the reactivity of iron to perform chemically challenging C–H bond functionalization reactions. Thus far, only a handful have been structurally characterized and remarkably little information exists regarding how these enzymes use common architecture set metallocenters facilitate diverse range Herein, we detail two SxtT GxtA different protein regions influence site-selectivity their catalyzed monohydroxylation We present high resolution crystal structures...

Abstract Nitriles are uncommon in nature and typically constructed from oximes through the oxidative decarboxylation of amino acid substrates or derivatization carboxylic acids. Here we report a third nitrile biosynthesis strategy featuring cyanobacterial synthase AetD. During eagle-killing neurotoxin, aetokthonotoxin, AetD transforms 2-aminopropionate portion 5,7-dibromo- l -tryptophan to nitrile. Employing combination structural, biochemical biophysical techniques, characterized as...

InfoMetricsFiguresRef. ACS Central ScienceASAPArticle This publication is Open Access under the license indicated. Learn More CiteCitationCitation and abstractCitation referencesMore citation options ShareShare onFacebookXWeChatLinkedInRedditEmailBlueskyJump toExpandCollapse First ReactionsMarch 10, 2025Promiscuity in Nature Extends to Protein Biosynthetic MachineryClick copy article linkArticle link copied!Thioesters, rather than oxo-esters, can be tolerated processed during translation...

Biocatalytic reactions embody many features of ideal chemical transformations, including the potential for impeccable selectivity, high catalytic efficiency, mild reaction conditions, and use environmentally benign reagents. These advantages have created a demand biocatalysts that expand portfolio complexity-generating available to synthetic chemists. However, trade-off often exists between substrate scope biocatalyst its selectivity limits application enzymes in synthesis. We recently...

Secondary metabolites are assembled by enzymes that often perform reactions with high selectivity and specificity. Many of these also tolerate variations in substrate structure, exhibiting promiscuity enables various applications a given biocatalyst. However, initial enzyme characterization studies frequently do not explore beyond the native substrates. This limited assessment scope contributes to difficulty identifying appropriate for specific synthetic applications. Here, we report natural...

Nitriles are uncommon in nature and typically constructed from oximes via the oxidative decarboxylation of amino acid substrates or derivatization carboxylic acids. Here we report a third strategy nitrile biosynthesis featuring cyanobacterial synthase AetD. During 'eagle-killing' neurotoxin, aetokthonotoxin, AetD converts alanyl side chain 5,7-dibromo-L-tryptophan to nitrile. Employing combination structural, biochemical, biophysical techniques, characterized as non-heme diiron enzyme that...

Despite their varied purposes, many indispensable molecules in medicine, materials, and asymmetric catalysis share a biaryl core. The necessity of joining arene building blocks to access these valuable compounds has inspired multiple approaches for bond formation challenged chemists develop increasingly concise robust methods this task. Oxidative coupling two C–H bonds offers an efficient strategy the C–C bond, however, fundamental challenges remain controlling reactivity selectivity uniting...

A single-component flavin-dependent halogenase, AetF, has emerged as an attractive biocatalyst for catalyzing halogenation. However, its flavin chemistry remains unexplored and cannot be predicted due to uniqueness in sequence structure compared other monooxygenases. Here, we investigated the reactions of AetF using transient kinetics. Our data revealed that NADP + binding is required formation C4a-hydroperoxy adenine dinucleotide (FAD) (FAD C4aOOH ), a key flavin-oxygen adduct generating...

Herein, we disclose the structural basis for substrate binding in TropB, which performs a synthetically challenging asymmetric oxidative dearomatization reaction with exquisite site- and stereoselectivity across range of substrates, providing foundation future protein engineering development efforts. Our hypothesis is informed by first crystal structure TropB molecular dynamics simulations corresponding computational model supported experimental data.

Herein, we disclose the structural basis for substrate binding in TropB, which performs a synthetically challenging asymmetric oxidative dearomatization reaction with exquisite site- and stereoselectivity across range of substrates, providing foundation future protein engineering development efforts. Our hypothesis is informed by first crystal structure TropB molecular dynamics simulations corresponding computational model supported experimental data.