title: Two Distinct Cyclodipeptide Synthases from a Marine Actinomycete Catalyze Biosynthesis of the Same Diketopiperazine Natural Product.
abstract: Diketopiperazine natural products are structurally diverse and offer many biological activities. Cyclodipeptide synthases (CDPSs) were recently unveiled as a novel enzyme family that employs aminoacyl-tRNAs as substrates for 2,5-diketopiperazine assembly. Here, the Nocardiopsis sp. CMB-M0232 genome is predicted to encode two CDPSs, NozA and NcdA. Metabolite profiles from E. coli expressing these genes and assays with purified recombinant enzymes revealed that NozA and NcdA catalyze cyclo(l-Trp-l-Trp) (1) biosynthesis from tryptophanyl-tRNA and do not accept other aromatic aminoacyl-tRNA substrates. Fidelity is uncommon among characterized CDPSs, making NozA and NcdA important CDPS family additions. Further, 1 was previously supported as a biosynthetic precursor of the nocardioazines; the current study suggests that Nocardiopsis sp. may derive this precursor from both NozA and NcdA. This study offers a rare example of a single bacterium encoding multiple phylogenetically distinct enzymes that yield the same secondary metabolite and provides tools for chemoenzymatic syntheses of indole alkaloid diketopiperazines.
authors.affiliation: Department of Chemistry, University of North Florida , 1 UNF Drive, Jacksonville, Florida 32224, United States.
authors.forename: Elle D
authors.initials: ED
authors.lastname: James
authors.affiliation: Department of Chemistry, University of North Florida , 1 UNF Drive, Jacksonville, Florida 32224, United States.
authors.forename: Bryan
authors.initials: B
authors.lastname: Knuckley
authors.affiliation: Department of Chemistry, Case Western Reserve University , Millis Science Center Room 216, 2074 Adelbert Road, Cleveland, Ohio 44106-7078, United States.
authors.forename: Norah
authors.initials: N
authors.lastname: Alqahtani
authors.affiliation: Department of Chemistry, Case Western Reserve University , Millis Science Center Room 216, 2074 Adelbert Road, Cleveland, Ohio 44106-7078, United States.
authors.forename: Suheel
authors.initials: S
authors.lastname: Porwal
authors.affiliation: Department of Chemistry, University of North Florida , 1 UNF Drive, Jacksonville, Florida 32224, United States.
authors.forename: Jisun
authors.initials: J
authors.lastname: Ban
authors.affiliation: Mass Spectrometry Facility, Indiana University , Department of Chemistry, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405, United States.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Karty
authors.affiliation: Department of Chemistry, Case Western Reserve University , Millis Science Center Room 216, 2074 Adelbert Road, Cleveland, Ohio 44106-7078, United States.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Viswanathan
authors.affiliation: Department of Chemistry, University of North Florida , 1 UNF Drive, Jacksonville, Florida 32224, United States.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Lane
mesh_terms: D000192:Actinomycetales / Q000201:enzymology* / Q000235:genetics; D002384:Catalysis; D020134:Catalytic Domain; D054659:Diketopiperazines / Q000378:metabolism*; D004151:Dipeptides / Q000096:biosynthesis; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D014369:Tryptophan-tRNA Ligase / Q000235:genetics / Q000378:metabolism
chemical_list: D054659:Diketopiperazines; D004151:Dipeptides; D011994:Recombinant Proteins; D014369:Tryptophan-tRNA Ligase; D010453:Peptide Synthases
keywords: biosynthesis; cyclodipeptide synthase; diketopiperazine; natural product; nonribosomal peptide; tRNA