Biosynthesis of the nargenicin A1 pyrrole moiety from Nocardia sp. CS682

Abstract

A number of structurally diverse natural products harboring pyrrole moieties possess a wide range of biological activities. Studies on biosynthesis of pyrrole ring have shown that pyrrole moieties are derived from L-proline. Nargenicin A(1), a saturated alicyclic polyketide from Nocardia sp. CS682, is a pyrrole-2-carboxylate ester of nodusmicin. We cloned and identified a set of four genes from Nocardia sp. CS682 that show sequence similarity to the respective genes involved in the biosynthesis of the pyrrole moieties of pyoluteorin in Pseudomonas fluorescens, clorobiocin in Streptomyces roseochromogenes subsp. Oscitans, coumermycin A(1) in Streptomyces rishiriensis, one of the pyrrole rings of undecylprodigiosin in Streptomyces coelicolor, and leupyrrins in Sorangium cellulosum. These genes were designated as ngnN4, ngnN5, ngnN3, and ngnN2. In this study, we presented the evidences that the pyrrole moiety of nargenicin A(1) was also derived from L-proline by the coordinated action of three proteins, NgnN4 (proline adenyltransferase), NgnN5 (proline carrier protein), and NgnN3 (flavine-dependent acyl-coenzyme A dehydrogenases). Biosynthesis of pyrrole moiety in nargenicin A(1) is initiated by NgnN4 that catalyzes ATP-dependent activation of L-proline into L-prolyl-AMP, and the latter is transferred to NgnN5 to create prolyl-S-peptidyl carrier protein (PCP). Later, NgnN3 catalyzes the two-step oxidation of prolyl-S-PCP into pyrrole-2-carboxylate. Thus, this study presents another example of a pyrrole moiety biosynthetic pathway that uses a set of three genes to convert L-proline into pyrrole-2-carboxylic acid moiety.

Enhanced Production of Nargenicin A1 and Generation of Novel Glycosylated Derivatives

“…The strains were seeded in brain heart infusion (BHI) broth at 37°C for 5 days. Nargenicin A 1 aglycon has been shown to be derived from common precursors as acetate and propionate [23], and the pyrrole moiety is presumed to be derived from L-proline [24,25]. In the present study, the influence of precursor substrates including ethanol, glucose, and glycerol as source of acetate, propanol as source of propionate, and L-proline contributing for pyrrole moiety, was evaluated on nargenicin A 1 biosynthesis.…”

Living on pyrrolic foundations – Advances in natural and artificial bioactive pyrrole derivatives

“…Studies have shown that biosynthesis of the 5-methylpyrrolyl-2-carboxyl moiety present in clorobiocin and coumermycin A 1 , the dichloropyrrolyl moiety in pyoluteorin, the pyrrolyl-2-carboxyl moiety in leupyrrins, and the first of the three pyrrole groups in undecylprodigiosin, can be all traced back to the pyrrole-2-carboxylate skeleton in all the cases, regardless of parent compounds and the microbial strain employed as a producing agent. In the case of leupyrrins, aminocoumarin antibiotics, clorobiocin and coumermycin A 1 , L-proline was identified as the precursor for the pyrrole rings, however, the pyrrole rings of undecylprodigiosin are formed in three separate enzymatic processes [51].…”

“…Its structure consists of a cis-fused octalin ring system linked to a pyrrole-2-carboxylic acid segment. Sushila Maharjan et al investigated the different biosynthetic routes of nargenicin A 1 , providing evidence that the pyrrole moiety present in the compound is also derived from L -proline, owing to the coordinated action of three proteins, NgnN4 (proline adenyltransferase), NgnN5 (proline carrier protein), and NgnN3 (flavine-dependent acyl-coenzyme A dehydrogenases) [51].…”

A Sweet Origin for the Key Congocidine Precursor 4‐Acetamidopyrrole‐2‐carboxylate

“…The diversity of these metabolites is mirrored in the multiple biosynthetic pathways leading to pyrrole groups. Six different biosynthetic pathways have been characterized to date, [1,2] involving various primary metabolite precursors, such as amino acids (glycine, proline, serine, threonine, and tryptophan), [1][2][3][4][5][6][7][8][9][10] dicarboxylic acids (malonate, oxaloacetate, and succinate), [1,2,7,8] or N-(5'-phosphoribosyl)anthranilate. [1] Pyrrolamides are a family of natural products, synthesized by Streptomyces and related actinobacteria, that all contain one or more pyrrole-2-carboxamide moieties in their structure.…”

“…Cgc11 catalyzes nucleotide triphosphate (NTP)-dependent conversion of 2 into the nucleotide diphosphate (NDP) derivative 3, which undergoes Cgc8-catalyzed oxidation of the C-6 hydroxy group to a carboxy group to yield NDP-2-acetamido-2-deoxyglucopyranuronic acid (4). Cgc9 catalyzes the decarboxylation of 4 to afford NDP-threo-2-acetamido-2-deoxy-pentopyran-4ulose (5). Reductive amination of the C-4 keto group of 5 is catalyzed by the putative pyridoxal-5-phosphate-dependent aminotransferase Cgc12.…”