Copalyl diphosphate synthase from Penicillium fellutanum (PfCPS) is an assembly-line terpene synthase that contains both prenyltransferase and class II cyclase activities. The prenyltransferase catalyzes processive chain elongation reactions using dimethylallyl diphosphate and three equivalents of isopentenyl diphosphate to yield geranylgeranyl diphosphate, which is then utilized as a substrate by the class II cyclase domain to generate copalyl diphosphate. Here, we report the 2.
View Article and Find Full Text PDFLysyl oxidase-2 (LOXL2) is a Cu and lysine tyrosylquinone (LTQ)-dependent amine oxidase that catalyzes the oxidative deamination of peptidyl lysine and hydroxylysine residues to promote crosslinking of extracellular matrix proteins. LTQ is post-translationally derived from Lys653 and Tyr689, but its biogenesis mechanism remains still elusive. A 2.
View Article and Find Full Text PDFThe regiospecific prenylation of an aromatic amino acid catalyzed by a dimethylallyl-l-tryptophan synthase (DMATS) is a key step in the biosynthesis of many fungal and bacterial natural products. DMATS enzymes share a common "ABBA" fold with divergent active site contours that direct alternative C-C, C-N, and C-O bond-forming trajectories. DMATS1 from catalyzes the reverse N-prenylation of l-Trp by generating an allylic carbocation from dimethylallyl diphosphate (DMAPP) that then alkylates the indole nitrogen of l-Trp.
View Article and Find Full Text PDFPseudomonas aeruginosa is an increasingly antibiotic-resistant pathogen that causes severe lung infections, burn wound infections, and diabetic foot infections. P. aeruginosa produces the siderophore pyochelin through the use of a non-ribosomal peptide synthetase (NRPS) biosynthetic pathway.
View Article and Find Full Text PDFCopalyl diphosphate (CPP) synthase from (PvCPS) is a bifunctional diterpene synthase with both prenyltransferase and class II cyclase activities. The prenyltransferase α domain catalyzes the condensation of C dimethylallyl diphosphate with three successively added C isopentenyl diphosphates (IPPs) to form C geranylgeranyl diphosphate (GGPP), which then undergoes a class II cyclization reaction at the βγ domain interface to generate CPP. The prenyltransferase α domain mediates oligomerization to form a 648-kD (αβγ) hexamer.
View Article and Find Full Text PDFThe magnificent chemodiversity of more than 95 000 terpenoid natural products identified to date largely originates from catalysis by two types of terpene synthases, prenyltransferases and cyclases. Prenyltransferases utilize 5-carbon building blocks in processive chain elongation reactions to generate linear C isoprenoid diphosphates ( ≥ 2), which in turn serve as substrates for terpene cyclases that convert these linear precursors into structurally complex hydrocarbon products containing multiple rings and stereocenters. Terpene cyclization reactions are the most complex organic transformations found in nature in that more than half of the substrate carbon atoms undergo changes in chemical bonding during a multistep reaction sequence proceeding through several carbocation intermediates.
View Article and Find Full Text PDFThe sesquiterpene cyclase -isozizaene synthase (EIZS) catalyzes the cyclization of farnesyl diphosphate to form the tricyclic precursor of the antibiotic albaflavenone. The hydrophobic active site is largely defined by aromatic residues that direct a multistep reaction sequence through multiple carbocation intermediates. The previous substitution of polar residues for a key aromatic residue, F96, converts EIZS into a high-fidelity sesquisabinene synthase: the F96S, F96M, and F96Q variants generate 78%, 91%, and 97% sesquisabinene A, respectively.
View Article and Find Full Text PDFThe unusual diterpene (C) synthase copalyl diphosphate synthase from Penicillium verruculosum (PvCPS) is the first bifunctional terpene synthase identified with both prenyltransferase and class II cyclase activities in a single polypeptide chain with αβγ domain architecture. The C-terminal prenyltransferase α domain generates geranylgeranyl diphosphate which is then cyclized to form copalyl diphosphate at the N-terminal βγ domain interface. We now demonstrate that PvCPS exists as a hexamer at high concentrations - a unique quaternary structure for known αβγ terpene synthases.
View Article and Find Full Text PDFHuman liver pyruvate kinase (hLPYK) converts phosphoenolpyruvate to pyruvate in the final step of glycolysis. hLPYK is allosterically activated by fructose-1,6-bisphosphate (Fru-1,6-BP). The allosteric site, as defined by previous structural studies, is located in domain C between the phosphate-binding loop (residues 444-449) and the allosteric loop (residues 527-533).
View Article and Find Full Text PDFNonribosomal peptide synthetases use tailoring domains to incorporate chemical diversity into the final natural product. A structurally unique set of tailoring domains are found to be stuffed within adenylation domains and have only recently begun to be characterized. PchF is the NRPS termination module in pyochelin biosynthesis and includes a stuffed methyltransferase domain responsible for S-adenosylmethionine (AdoMet)-dependent N-methylation.
View Article and Find Full Text PDFCurr Opin Struct Biol
December 2018
Microbes synthesize small, iron-chelating molecules known as siderophores to acquire iron from the environment. One way siderophores are generated is by nonribosomal peptide synthetases (NRPSs). The bioactive peptides generated by NRPS enzymes have unique chemical features, which are incorporated by accessory and tailoring domains or proteins.
View Article and Find Full Text PDFThiazolinyl imine reductases catalyze the NADPH-dependent reduction of a thiazoline to a thiazolidine, a required step in the formation of the siderophores yersiniabactin (Yersinia spp.) and pyochelin (Pseudomonas aeruginosa). These stand-alone nonribosomal peptide tailoring domains are structural homologues of sugar oxidoreductases.
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