scholarly journals Glycosulfatase-Encoding Gene Cluster in Bifidobacterium breve UCC2003

2016 ◽  
Vol 82 (22) ◽  
pp. 6611-6623 ◽  
Author(s):  
Muireann Egan ◽  
Hao Jiang ◽  
Mary O'Connell Motherway ◽  
Stefan Oscarson ◽  
Douwe van Sinderen
Keyword(s):  
Gastrointestinal Tract ◽  
Gut Microbiota ◽  
Gene Cluster ◽  
Digestive Tract ◽  
Gene Clusters ◽  
Content Type ◽  
Reading Frame ◽  
Bifidobacterium Breve ◽  
Breastfed Infants ◽  
Encoding Gene

ABSTRACTBifidobacteria constitute a specific group of commensal bacteria typically found in the gastrointestinal tract (GIT) of humans and other mammals.Bifidobacterium brevestrains are numerically prevalent among the gut microbiota of many healthy breastfed infants. In the present study, we investigated glycosulfatase activity in a bacterial isolate from a nursling stool sample,B. breveUCC2003. Two putative sulfatases were identified on the genome ofB. breveUCC2003. The sulfated monosaccharideN-acetylglucosamine-6-sulfate (GlcNAc-6-S) was shown to support the growth ofB. breveUCC2003, whileN-acetylglucosamine-3-sulfate,N-acetylgalactosamine-3-sulfate, andN-acetylgalactosamine-6-sulfate did not support appreciable growth. By using a combination of transcriptomic and functional genomic approaches, a gene cluster designatedats2was shown to be specifically required for GlcNAc-6-S metabolism. Transcription of theats2cluster is regulated by a repressor open reading frame kinase (ROK) family transcriptional repressor. This study represents the first description of glycosulfatase activity within theBifidobacteriumgenus.IMPORTANCEBifidobacteria are saccharolytic organisms naturally found in the digestive tract of mammals and insects.Bifidobacterium brevestrains utilize a variety of plant- and host-derived carbohydrates that allow them to be present as prominent members of the infant gut microbiota as well as being present in the gastrointestinal tract of adults. In this study, we introduce a previously unexplored area of carbohydrate metabolism in bifidobacteria, namely, the metabolism of sulfated carbohydrates.B. breveUCC2003 was shown to metabolizeN-acetylglucosamine-6-sulfate (GlcNAc-6-S) through one of two sulfatase-encoding gene clusters identified on its genome. GlcNAc-6-S can be found in terminal or branched positions of mucin oligosaccharides, the glycoprotein component of the mucous layer that covers the digestive tract. The results of this study provide further evidence of the ability of this species to utilize mucin-derived sugars, a trait which may provide a competitive advantage in both the infant gut and adult gut.

scholarly journals Overproduction of Ristomycin A by Activation of a Silent Gene Cluster in Amycolatopsis japonicum MG417-CF17

2014 ◽  
Vol 58 (10) ◽  
pp. 6185-6196 ◽  
Author(s):  
Marius Spohn ◽  
Norbert Kirchner ◽  
Andreas Kulik ◽  
Angelika Jochim ◽  
Felix Wolf ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gene Cluster ◽  
High Performance ◽  
Pathogenic Bacteria ◽  
Genome Mining ◽  
Gene Clusters ◽  
Von Willebrand Disease ◽  
Biosynthesis Gene Cluster ◽  
Content Type ◽  
Bioinformatic Tools

ABSTRACTThe emergence of antibiotic-resistant pathogenic bacteria within the last decades is one reason for the urgent need for new antibacterial agents. A strategy to discover new anti-infective compounds is the evaluation of the genetic capacity of secondary metabolite producers and the activation of cryptic gene clusters (genome mining). One genus known for its potential to synthesize medically important products isAmycolatopsis. However,Amycolatopsis japonicumdoes not produce an antibiotic under standard laboratory conditions. In contrast to mostAmycolatopsisstrains,A. japonicumis genetically tractable with different methods. In order to activate a possible silent glycopeptide cluster, we introduced a gene encoding the transcriptional activator of balhimycin biosynthesis, thebbrgene fromAmycolatopsis balhimycina(bbrAba), intoA. japonicum. This resulted in the production of an antibiotically active compound. Following whole-genome sequencing ofA. japonicum, 29 cryptic gene clusters were identified by genome mining. One of these gene clusters is a putative glycopeptide biosynthesis gene cluster. Using bioinformatic tools, ristomycin (syn. ristocetin), a type III glycopeptide, which has antibacterial activity and which is used for the diagnosis of von Willebrand disease and Bernard-Soulier syndrome, was deduced as a possible product of the gene cluster. Chemical analyses by high-performance liquid chromatography and mass spectrometry (HPLC-MS), tandem mass spectrometry (MS/MS), and nuclear magnetic resonance (NMR) spectroscopy confirmed thein silicoprediction that the recombinantA. japonicum/pRM4-bbrAbasynthesizes ristomycin A.

scholarly journals Plasmid-Borne Type E Neurotoxin Gene Clusters in Clostridium botulinum Strains

2013 ◽  
Vol 79 (12) ◽  
pp. 3856-3859 ◽  
Author(s):  
Zhen Zhang ◽  
Hannamari Hintsa ◽  
Ying Chen ◽  
Hannu Korkeala ◽  
Miia Lindström
Keyword(s):  
Gene Cluster ◽  
Gel Electrophoresis ◽  
Clostridium Botulinum ◽  
Southern Hybridization ◽  
Gene Clusters ◽  
Pulsed Field Gel Electrophoresis ◽  
Content Type ◽  
Pulsed Field ◽  
Large Plasmids

ABSTRACTA collection of 36Clostridium botulinumtype E strains was examined by pulsed-field gel electrophoresis (PFGE) and Southern hybridization with probes targeted tobotEandorfX1in the neurotoxin gene cluster. Three strains were found to contain neurotoxin subtype E1 gene clusters in large plasmids of about 146 kb in size.

scholarly journals Fur-Dam Regulatory Interplay at an Internal Promoter of the Enteroaggregative Escherichia coli Type VI Secretion sci1 Gene Cluster

2020 ◽  
Vol 202 (10) ◽  
Author(s):  
Yannick R. Brunet ◽  
Christophe S. Bernard ◽  
Eric Cascales
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Gene Clusters ◽  
Secretion System ◽  
Target Cells ◽  
Type Vi Secretion System ◽  
Content Type ◽  
Internal Promoter ◽  
E Coli ◽  
Type Vi Secretion

ABSTRACT The type VI secretion system (T6SS) is a weapon for delivering effectors into target cells that is widespread in Gram-negative bacteria. The T6SS is a highly versatile machine, as it can target both eukaryotic and prokaryotic cells, and it has been proposed that T6SSs are adapted to the specific needs of each bacterium. The expression of T6SS gene clusters and the activation of the secretion apparatus are therefore tightly controlled. In enteroaggregative Escherichia coli (EAEC), the sci1 T6SS gene cluster is subject to a complex regulation involving both the ferric uptake regulator (Fur) and DNA adenine methylase (Dam)-dependent DNA methylation. In this study, an additional, internal, promoter was identified within the sci1 gene cluster using +1 transcriptional mapping. Further analyses demonstrated that this internal promoter is controlled by a mechanism strictly identical to that of the main promoter. The Fur binding box overlaps the −10 transcriptional element and a Dam methylation site, GATC-32. Hence, the expression of the distal sci1 genes is repressed and the GATC-32 site is protected from methylation in iron-rich conditions. The Fur-dependent protection of GATC-32 was confirmed by an in vitro methylation assay. In addition, the methylation of GATC-32 negatively impacted Fur binding. The expression of the sci1 internal promoter is therefore controlled by iron availability through Fur regulation, whereas Dam-dependent methylation maintains a stable ON expression in iron-limited conditions. IMPORTANCE Bacteria use weapons to deliver effectors into target cells. One of these weapons, the type VI secretion system (T6SS), assembles a contractile tail acting as a spring to propel a toxin-loaded needle. Its expression and activation therefore need to be tightly regulated. Here, we identified an internal promoter within the sci1 T6SS gene cluster in enteroaggregative E. coli. We show that this internal promoter is controlled by Fur and Dam-dependent methylation. We further demonstrate that Fur and Dam compete at the −10 transcriptional element to finely tune the expression of T6SS genes. We propose that this elegant regulatory mechanism allows the optimum production of the T6SS in conditions where enteroaggregative E. coli encounters competing species.

scholarly journals The Gene Cluster forpara-Nitrophenol Catabolism Is Responsible for 2-Chloro-4-Nitrophenol Degradation in Burkholderia sp. Strain SJ98

2014 ◽  
Vol 80 (19) ◽  
pp. 6212-6222 ◽  
Author(s):  
Jun Min ◽  
Jun-Jie Zhang ◽  
Ning-Yi Zhou
Keyword(s):  
Gene Cluster ◽  
Gene Knockout ◽  
Gene Clusters ◽  
Sole Source ◽  
Pcr Analysis ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
Biochemical Analyses ◽  
Nitrophenol Degradation

ABSTRACTBurkholderiasp. strain SJ98 (DSM 23195) utilizes 2-chloro-4-nitrophenol (2C4NP) orpara-nitrophenol (PNP) as a sole source of carbon and energy. Here, by genetic and biochemical analyses, a 2C4NP catabolic pathway different from those of all other 2C4NP utilizers was identified with chloro-1,4-benzoquinone (CBQ) as an intermediate. Reverse transcription-PCR analysis showed that all of thepnpgenes in thepnpABA1CDEFcluster were located in a single operon, which is significantly different from the genetic organization of all other previously reported PNP degradation gene clusters, in which the structural genes were located in three different operons. All of the Pnp proteins were purified to homogeneity as His-tagged proteins. PnpA, a PNP 4-monooxygenase, was found to be able to catalyze the monooxygenation of 2C4NP to CBQ. PnpB, a 1,4-benzoquinone reductase, has the ability to catalyze the reduction of CBQ to chlorohydroquinone. Moreover, PnpB is also able to enhance PnpA activityin vitroin the conversion of 2C4NP to CBQ. Genetic analyses indicated thatpnpAplays an essential role in the degradation of both 2C4NP and PNP by gene knockout and complementation. In addition to being responsible for the lower pathway of PNP catabolism, PnpCD, PnpE, and PnpF were also found to be likely involved in that of 2C4NP catabolism. These results indicated that the catabolism of 2C4NP and that of PNP share the same gene cluster in strain SJ98. These findings fill a gap in our understanding of the microbial degradation of 2C4NP at the molecular and biochemical levels.

scholarly journals Biosynthesis of Fusarubins Accounts for Pigmentation of Fusarium fujikuroi Perithecia

2012 ◽  
Vol 78 (12) ◽  
pp. 4468-4480 ◽  
Author(s):  
Lena Studt ◽  
Philipp Wiemann ◽  
Karin Kleigrewe ◽  
Hans-Ulrich Humpf ◽  
Bettina Tudzynski
Keyword(s):  
Secondary Metabolites ◽  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Biological Function ◽  
Fusarium Fujikuroi ◽  
Diverse Group ◽  
Fruiting Bodies ◽  
Content Type ◽  
Encoding Gene

ABSTRACTFusarium fujikuroiproduces a variety of secondary metabolites, of which polyketides form the most diverse group. Among these are the highly pigmented naphthoquinones, which have been shown to possess different functional properties for the fungus. A group of naphthoquinones, polyketides related to fusarubin, were identified inFusariumspp. more than 60 years ago, but neither the genes responsible for their formation nor their biological function has been discovered to date. In addition, although it is known that the sexual fruiting bodies in which the progeny of the fungus develops are darkly colored by a polyketide synthase (PKS)-derived pigment, the structure of this pigment has never been elucidated. Here we present data that link the fusarubin-type polyketides to a defined gene cluster, which we designatefsr, and demonstrate that the fusarubins are the pigments responsible for the coloration of the perithecia. We studied their regulation and the function of the single genes within the cluster by a combination of gene replacements and overexpression of the PKS-encoding gene, and we present a model for the biosynthetic pathway of the fusarubins based on these data.

scholarly journals A Novel AdpA Homologue Negatively Regulates Morphological Differentiation inStreptomyces xiamenensis318

2019 ◽  
Vol 85 (7) ◽  
Author(s):  
Xu-Liang Bu ◽  
Jing-Yi Weng ◽  
Bei-Bei He ◽  
Min-Juan Xu ◽  
Jun Xu
Keyword(s):  
Cell Growth ◽  
Secondary Metabolism ◽  
Gene Cluster ◽  
Morphological Differentiation ◽  
Gene Clusters ◽  
Transcriptional Level ◽  
Negative Effects ◽  
Promoter Regions ◽  
Content Type ◽  
Enhanced Production

ABSTRACTThe pleiotropic transcriptional regulator AdpA positively controls morphological differentiation and regulates secondary metabolism in mostStreptomycesspecies.Streptomyces xiamenensis318 has a linear chromosome 5.96 Mb in size. How AdpA affects secondary metabolism and morphological differentiation in such a naturally minimized genomic background is unknown. Here, we demonstrated that AdpASx, an AdpA orthologue inS. xiamenensis, negatively regulates cell growth and sporulation and bidirectionally regulates the biosynthesis of xiamenmycin and polycyclic tetramate macrolactams (PTMs) inS. xiamenensis318. Overexpression of theadpASxgene inS. xiamenensis318 had negative effects on morphological differentiation and resulted in reduced transcription of putativessgA,ftsZ,ftsH,amfC,whiB,wblA1,wblA2,wblE, and a gene encoding sporulation-associated protein (sxim_29740), whereas the transcription of putativebldDandbldAgenes was upregulated. Overexpression ofadpASxled to significantly enhanced production of xiamenmycin but had detrimental effects on the production of PTMs. As expected, the transcriptional level of theximgene cluster was upregulated, whereas the PTM gene cluster was downregulated. Moreover, AdpASxnegatively regulated the transcription of its own gene. Electrophoretic mobility shift assays revealed that AdpASxcan bind the promoter regions of structural genes of both theximand PTM gene clusters as well as to the promoter regions of genes potentially involved in the cell growth and differentiation ofS. xiamenensis318. We report that an AdpA homologue has negative effects on morphological differentiation inS. xiamenensis318, a finding confirmed when AdpASxwas introduced into the heterologous hostStreptomyces lividansTK24.IMPORTANCEAdpA is a key regulator of secondary metabolism and morphological differentiation inStreptomycesspecies. However, AdpA had not been reported to negatively regulate morphological differentiation. Here, we characterized the regulatory role of AdpASxinStreptomyces xiamenensis318, which has a naturally streamlined genome. In this strain, AdpASxnegatively regulated cell growth and morphological differentiation by directly controlling genes associated with these functions. AdpASxalso bidirectionally controlled the biosynthesis of xiamenmycin and PTMs by directly regulating their gene clusters rather than through other regulators. Our findings provide additional evidence for the versatility of AdpA in regulating morphological differentiation and secondary metabolism inStreptomyces.

scholarly journals Two Master Switch Regulators Trigger A40926 Biosynthesis in Nonomuraea sp. Strain ATCC 39727

2015 ◽  
Vol 197 (15) ◽  
pp. 2536-2544 ◽  
Author(s):  
Letizia Lo Grasso ◽  
Sonia Maffioli ◽  
Margherita Sosio ◽  
Mervyn Bibb ◽  
Anna Maria Puglia ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Antibiotic Production ◽  
Regulatory Protein ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Regulatory Mechanisms ◽  
Antibiotic Biosynthesis ◽  
Strain Atcc ◽  
Protein Coding ◽  
Content Type

ABSTRACTThe actinomyceteNonomuraeasp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of dalbavancin. Biosynthesis of A40926 is encoded by thedbvgene cluster, which contains 37 protein-coding sequences that participate in antibiotic biosynthesis, regulation, immunity, and export. In addition to the positive regulatory protein Dbv4, the A40926-biosynthetic gene cluster encodes two additional putative regulators, Dbv3 and Dbv6. Independent mutations in these genes, combined with bioassays and liquid chromatography-mass spectrometry (LC-MS) analyses, demonstrated that Dbv3 and Dbv4 are both required for antibiotic production, while inactivation ofdbv6had no effect. In addition, overexpression ofdbv3led to higher levels of A40926 production. Transcriptional and quantitative reverse transcription (RT)-PCR analyses showed that Dbv4 is essential for the transcription of two operons,dbv14-dbv8anddbv30-dbv35, while Dbv3 positively controls the expression of four monocistronic transcription units (dbv4,dbv29,dbv36, anddbv37) and of six operons (dbv2-dbv1,dbv14-dbv8,dbv17-dbv15,dbv21-dbv20,dbv24-dbv28, anddbv30-dbv35). We propose a complex and coordinated model of regulation in which Dbv3 directly or indirectly activates transcription ofdbv4and controls biosynthesis of 4-hydroxyphenylglycine and the heptapeptide backbone, A40926 export, and some tailoring reactions (mannosylation and hexose oxidation), while Dbv4 directly regulates biosynthesis of 3,5-dihydroxyphenylglycine and other tailoring reactions, including the four cross-links, halogenation, glycosylation, and acylation.IMPORTANCEThis report expands knowledge of the regulatory mechanisms used to control the biosynthesis of the glycopeptide antibiotic A40926 in the actinomyceteNonomuraeasp. strain ATCC 39727. A40926 is the precursor of dalbavancin, approved for treatment of skin infections by Gram-positive bacteria. Therefore, understanding the regulation of its biosynthesis is also of industrial importance. So far, the regulatory mechanisms used to control two other similar glycopeptides (balhimycin and teicoplanin) have been elucidated, and beyond a common step, different clusters seem to have devised different strategies to control glycopeptide production. Thus, our work provides one more example of the pitfalls of deducing regulatory roles from bioinformatic analyses only, even when analyzing gene clusters directing the synthesis of structurally related compounds.

scholarly journals Discovery of Gene Cluster for Mycosporine-Like Amino Acid Biosynthesis from Actinomycetales Microorganisms and Production of a Novel Mycosporine-Like Amino Acid by Heterologous Expression

2014 ◽  
Vol 80 (16) ◽  
pp. 5028-5036 ◽  
Author(s):  
Kiyoko T. Miyamoto ◽  
Mamoru Komatsu ◽  
Haruo Ikeda
Keyword(s):  
Amino Acid ◽  
Gene Cluster ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Dependent Manner ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria

ABSTRACTMycosporines and mycosporine-like amino acids (MAAs), including shinorine (mycosporine-glycine-serine) and porphyra-334 (mycosporine-glycine-threonine), are UV-absorbing compounds produced by cyanobacteria, fungi, and marine micro- and macroalgae. These MAAs have the ability to protect these organisms from damage by environmental UV radiation. Although no reports have described the production of MAAs and the corresponding genes involved in MAA biosynthesis from Gram-positive bacteria to date, genome mining of the Gram-positive bacterial database revealed that two microorganisms belonging to the orderActinomycetales,Actinosynnema mirumDSM 43827 andPseudonocardiasp. strain P1, possess a gene cluster homologous to the biosynthetic gene clusters identified from cyanobacteria. When the two strains were grown in liquid culture,Pseudonocardiasp. accumulated a very small amount of MAA-like compound in a medium-dependent manner, whereasA. mirumdid not produce MAAs under any culture conditions, indicating that the biosynthetic gene cluster ofA. mirumwas in a cryptic state in this microorganism. In order to characterize these biosynthetic gene clusters, each biosynthetic gene cluster was heterologously expressed in an engineered host,Streptomyces avermitilisSUKA22. Since the resultant transformants carrying the entire biosynthetic gene cluster controlled by an alternative promoter produced mainly shinorine, this is the first confirmation of a biosynthetic gene cluster for MAA from Gram-positive bacteria. Furthermore,S. avermitilisSUKA22 transformants carrying the biosynthetic gene cluster for MAA ofA. mirumaccumulated not only shinorine and porphyra-334 but also a novel MAA. Structure elucidation revealed that the novel MAA is mycosporine-glycine-alanine, which substitutesl-alanine for thel-serine of shinorine.

scholarly journals Expanded Natural Product Diversity Revealed by Analysis of Lanthipeptide-Like Gene Clusters in Actinobacteria

2015 ◽  
Vol 81 (13) ◽  
pp. 4339-4350 ◽  
Author(s):  
Qi Zhang ◽  
James R. Doroghazi ◽  
Xiling Zhao ◽  
Mark C. Walker ◽  
Wilfred A. van der Donk
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Gene Cluster ◽  
Posttranslational Modifications ◽  
Large Scale ◽  
Biological Activities ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
Content Type ◽  
Modified Peptides

ABSTRACTLanthionine-containing peptides (lanthipeptides) are a rapidly growing family of polycyclic peptide natural products belonging to the large class of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Lanthipeptides are widely distributed in taxonomically distant species, and their currently known biosynthetic systems and biological activities are diverse. Building on the recent natural product gene cluster family (GCF) project, we report here large-scale analysis of lanthipeptide-like biosynthetic gene clusters fromActinobacteria. Our analysis suggests that lanthipeptide biosynthetic pathways, and by extrapolation the natural products themselves, are much more diverse than currently appreciated and contain many different posttranslational modifications. Furthermore, lanthionine synthetases are much more diverse in sequence and domain topology than currently characterized systems, and they are used by the biosynthetic machineries for natural products other than lanthipeptides. The gene cluster families described here significantly expand the chemical diversity and biosynthetic repertoire of lanthionine-related natural products. Biosynthesis of these novel natural products likely involves unusual and unprecedented biochemistries, as illustrated by several examples discussed in this study. In addition, class IV lanthipeptide gene clusters are shown not to be silent, setting the stage to investigate their biological activities.

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