scholarly journals Genomic Island TnSmu2 of Streptococcus mutans Harbors a Nonribosomal Peptide Synthetase-Polyketide Synthase Gene Cluster Responsible for the Biosynthesis of Pigments Involved in Oxygen and H2O2 Tolerance

2010 ◽  
Vol 76 (17) ◽  
pp. 5815-5826 ◽  
Author(s):  
Chenggang Wu ◽  
Robert Cichewicz ◽  
Yihong Li ◽  
Jinman Liu ◽  
Bruce Roe ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Streptococcus Mutans ◽  
High Performance ◽  
Polyketide Synthase ◽  
Genomic Island ◽  
Accessory Proteins ◽  
Nonribosomal Peptide ◽  
Peptide Synthetases ◽  
Mutant Strains ◽  
Polyketide Synthase Gene

ABSTRACT The oral biofilm community consists of >800 microbial species, among which Streptococcus mutans is considered a primary pathogen for dental caries. The genomic island TnSmu2 of S. mutans comprises >2% of the genome. In this study, we demonstrate that TnSmu2 harbors a gene cluster encoding nonribosomal peptide synthetases (NRPS), polyketide synthases (PKS), and accessory proteins and regulators involved in nonribosomal peptide (NRP) and polyketide (PK) biosynthesis. Interestingly, the sequences of these genes and their genomic organizations and locations are highly divergent among different S. mutans strains, yet each TnSmu2 region encodes NRPS/PKS and accessory proteins. Mutagenesis of the structural genes and putative regulatory genes in strains UA159, UA140, and MT4653 resulted in colonies that were devoid of their yellow pigmentation (for strains UA140 and MT4653). In addition, these mutant strains also displayed retarded growth under aerobic conditions and in the presence of H2O2. High-performance liquid chromatography profiling of cell surface extracts identified unique peaks that were missing in the mutant strains, and partial characterization of the purified product from UA159 demonstrated that it is indeed a hybrid NRP/PK, as predicted. A genomic survey of 94 clinical S. mutans isolates suggests that the TnSmu2 gene cluster may be more prevalent than previously recognized.

scholarly journals Inhibition of Grape Crown Gall by Agrobacterium vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase

2016 ◽  
Vol 29 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Desen Zheng ◽  
Thomas J. Burr
Keyword(s):  
Crown Gall ◽  
Polyketide Synthase ◽  
Wild Type ◽  
Tissue Necrosis ◽  
Agrobacterium Vitis ◽  
Nonribosomal Peptide ◽  
Crown Gall Disease ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Polyketide Synthase Gene

Agrobacterium vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730+) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730+ indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.

scholarly journals The Fusarium verticillioides FUM Gene Cluster Encodes a Zn(II)2Cys6 Protein That Affects FUM Gene Expression and Fumonisin Production

2007 ◽  
Vol 6 (7) ◽  
pp. 1210-1218 ◽  
Author(s):  
Daren W. Brown ◽  
Robert A. E. Butchko ◽  
Mark Busman ◽  
Robert H. Proctor
Keyword(s):  
Gene Cluster ◽  
Polyketide Synthase ◽  
Fusarium Verticillioides ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Regulatory Proteins ◽  
Wild Type ◽  
Polyketide Synthase Gene ◽  
Splice Forms ◽  
Self Protection

ABSTRACT Fumonisins are mycotoxins produced by some Fusarium species and can contaminate maize or maize products. Ingestion of fumonisins is associated with diseases, including cancer and neural tube defects, in humans and animals. In fungi, genes involved in the synthesis of mycotoxins and other secondary metabolites are often located adjacent to each other in gene clusters. Such genes can encode structural enzymes, regulatory proteins, and/or proteins that provide self-protection. The fumonisin biosynthetic gene cluster includes 16 genes, none of which appear to play a role in regulation. In this study, we identified a previously undescribed gene (FUM21) located adjacent to the fumonisin polyketide synthase gene, FUM1. The presence of a Zn(II)2Cys6 DNA-binding domain in the predicted protein suggested that FUM21 was involved in transcriptional regulation. FUM21 deletion (Δfum21) mutants produce little to no fumonisin in cracked maize cultures but some FUM1 and FUM8 transcripts in a liquid GYAM medium. Complementation of a Δfum21 mutant with a wild-type copy of the gene restored fumonisin production. Analysis of FUM21 cDNAs identified four alternative splice forms (ASFs), and microarray analysis indicated the ASFs were differentially expressed. Based on these data, we present a model for how FUM21 ASFs may regulate fumonisin biosynthesis.

scholarly journals Cloning and sequence analysis of the putative rifamycin polyketide synthase gene cluster fromAmycolatopsis mediterranei

1998 ◽  
Vol 159 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Thomas Schupp ◽  
Christiane Toupet ◽  
Nathalie Engel ◽  
Stephen Goff
Keyword(s):  
Sequence Analysis ◽  
Gene Cluster ◽  
Polyketide Synthase ◽  
Polyketide Synthase Gene

scholarly journals Gibepyrone Biosynthesis in the Rice PathogenFusarium fujikuroiIs Facilitated by a Small Polyketide Synthase Gene Cluster

2016 ◽  
Vol 291 (53) ◽  
pp. 27403-27420 ◽  
Author(s):  
Slavica Janevska ◽  
Birgit Arndt ◽  
Eva-Maria Niehaus ◽  
Immo Burkhardt ◽  
Sarah M. Rösler ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Polyketide Synthase ◽  
Polyketide Synthase Gene

scholarly journals Genome-based survey of nonribosomal peptide synthetase and polyketide synthase gene clusters in type strains of the genus Microtetraspora

2016 ◽  
Vol 69 (9) ◽  
pp. 712-718 ◽  
Author(s):  
Hisayuki Komaki ◽  
Natsuko Ichikawa ◽  
Tomohiko Tamura ◽  
Akio Oguchi ◽  
Moriyuki Hamada ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Gene Clusters ◽  
Nonribosomal Peptide Synthetase ◽  
Nonribosomal Peptide ◽  
Peptide Synthetase ◽  
Polyketide Synthase Gene ◽  
Type Strains

scholarly journals Cloning, Sequencing, and Functional Analysis of an Iterative Type I Polyketide Synthase Gene Cluster for Biosynthesis of the Antitumor Chlorinated Polyenone Neocarzilin in “Streptomyces carzinostaticus”

2004 ◽  
Vol 48 (9) ◽  
pp. 3468-3476 ◽  
Author(s):  
Miyuki Otsuka ◽  
Koji Ichinose ◽  
Isao Fujii ◽  
Yutaka Ebizuka
Keyword(s):  
Gene Cluster ◽  
Polyketide Synthase ◽  
Streptomyces Coelicolor ◽  
Open Reading Frames ◽  
Modular Organization ◽  
Type I ◽  
Orf3 Protein ◽  
Polyketide Synthase Gene ◽  
Polyketide Chain ◽  
Reading Frames

ABSTRACT Neocarzilins (NCZs) are antitumor chlorinated polyenones produced by “Streptomyces carzinostaticus” var. F-41. The gene cluster responsible for the biosynthesis of NCZs was cloned and characterized. DNA sequence analysis of a 33-kb region revealed a cluster of 14 open reading frames (ORFs), three of which (ORF4, ORF5, and ORF6) encode type I polyketide synthase (PKS), which consists of four modules. Unusual features of the modular organization is the lack of an obvious acyltransferase domain on modules 2 and 4 and the presence of longer interdomain regions more than 200 amino acids in length on each module. Involvement of the PKS genes in NCZ biosynthesis was demonstrated by heterologous expression of the cluster in Streptomyces coelicolor CH999, which produced the apparent NCZ biosynthetic intermediates dechloroneocarzillin A and dechloroneocarzilin B. Disruption of ORF5 resulted in a failure of NCZ production, providing further evidence that the cluster is essential for NCZ biosynthesis. Mechanistic consideration of NCZ formation indicates the iterative use of at least one module of the PKS, which subsequently releases its product by decarboxylation to generate an NCZ skeleton, possibly catalyzed by a type II thioesterase encoded by ORF7. This is a novel type I PKS system of bacterial origin for the biosynthesis of a reduced polyketide chain. Additionally, the protein encoded by ORF3, located upstream of the PKS genes, closely resembles the FADH2-dependent halogenases involved in the formation of halometabolites. The ORF3 protein could be responsible for the halogenation of NCZs, presenting a unique example of a halogenase involved in the biosynthesis of an aliphatic halometabolite.

scholarly journals Unique features of the ketosynthase domain in a nonribosomal peptide synthetase–polyketide synthase hybrid enzyme, tenuazonic acid synthetase 1

2020 ◽  
Vol 295 (33) ◽  
pp. 11602-11612 ◽  
Author(s):  
Choong-Soo Yun ◽  
Kazuki Nishimoto ◽  
Takayuki Motoyama ◽  
Takeshi Shimizu ◽  
Tomoya Hino ◽  
...  
Keyword(s):  
Amino Acid ◽  
Polyketide Synthase ◽  
Binding Pocket ◽  
Single Amino Acid ◽  
Tenuazonic Acid ◽  
Nonribosomal Peptide ◽  
Hybrid Enzyme ◽  
Peptide Synthetases ◽  
Multienzyme Complexes ◽  
Ketosynthase Domain

Many microbial secondary metabolites are produced by multienzyme complexes comprising nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs). The ketosynthase (KS) domains of polyketide synthase normally catalyze the decarboxylative Claisen condensation of acyl and malonyl blocks to extend the polyketide chain. However, the terminal KS domain in tenuazonic acid synthetase 1 (TAS1) from the fungus Pyricularia oryzae conducts substrate cyclization. Here, we report on the unique features of the KS domain in TAS1. We observed that this domain is monomeric, not dimeric as is typical for KSs. Analysis of a 1.68-Å resolution crystal structure suggests that the substrate cyclization is triggered via proton abstraction from the active methylene moiety in the substrate by a catalytic His-322 residue. Additionally, we show that TAS1 KS promiscuously accepts aminoacyl substrates and that this promiscuity can be increased by a single amino acid substitution in the substrate-binding pocket of the enzyme. These findings provide insight into a KS domain that accepts the amino acid–containing substrate in an NRPS–PKS hybrid enzyme and provide hints to the substrate cyclization mechanism performed by the KS domain in the biosynthesis of the mycotoxin tenuazonic acid.

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