The metabolic and regulatory networks of carbohydrate utilization of Thermotoga maritima
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ABSTRACT:
ORGANISM(S): Thermotoga maritima MSB8
PROVIDER: GSE47615 | GEO | 2013/08/02
SECONDARY ACCESSION(S): PRJNA207002
REPOSITORIES: GEO
Similar Datasets
Project description:In this study, we combined a subsystem-based comparative genomic approach with experimental validation to reconstruct the metabolic and regulatory networks of carbohydrate utilization in 11 complete genomes from the Thermotogales order. Exression profiling studies were performed using total RNA isolated from mid log phase cultures of T. maritima grown on minimal media with distinct carbon sources.
2013-08-02 | E-GEOD-47615 | biostudies-arrayexpress
Project description:Hyperthermophilic bacteria from the Thermotogales lineage can produce hydrogen by fermenting a wide range of carbohydrates. Previous experimental studies identified a large fraction of genes committed to carbohydrate degradation and utilization in the model bacterium Thermotoga maritima. Knowledge of these genes enabled comprehensive reconstruction of biochemical pathways comprising the carbohydrate utilization network. However, transcriptional factors (TFs) and regulatory mechanisms driving this network remained largely unknown. Here, we used an integrated approach based on comparative analysis of genomic and transcriptomic data for the reconstruction of the carbohydrate utilization regulatory networks in 11 Thermotogales genomes. We identified DNA-binding motifs and regulons for 19 orthologous TFs in the Thermotogales. The inferred regulatory network in T. maritima contains 181 genes encoding TFs, sugar catabolic enzymes and ABC-family transporters. In contrast to many previously described bacteria, a transcriptional regulation strategy of Thermotoga does not employ global regulatory factors. The reconstructed regulatory network in T. maritima was validated by gene expression profiling on a panel of mono- and disaccharides and by in vitro DNA-binding assays. The observed upregulation of genes involved in catabolism of pectin, trehalose, cellobiose, arabinose, rhamnose, xylose, glucose, galactose, and ribose showed a strong correlation with the UxaR, TreR, BglR, CelR, AraR, RhaR, XylR, GluR, GalR, and RbsR regulons. Ultimately, this study elucidated the transcriptional regulatory network and mechanisms controlling expression of carbohydrate utilization genes in T. maritima. In addition to improving the functional annotations of associated transporters and catabolic enzymes, this research provides novel insights into the evolution of regulatory networks in Thermotogales.
| S-EPMC3750489 | biostudies-literature
Project description:The metabolic and regulatory networks of carbohydrate utilization of Thermotoga maritima
| PRJNA207002 | ENA
Project description:Bifidobacteria are among the earliest colonizers of the human gut, conferring multiple health benefits. While multiple Bifidobacterium strains are used as probiotics, accumulating evidence suggests that the individual responses to probiotic supplementation may vary, likely due to a variety of factors, including strain type(s), gut community composition, dietary habits of the consumer, and other health/lifestyle conditions. Given the saccharolytic nature of bifidobacteria, the carbohydrate composition of the diet is one of the primary factors dictating the colonization efficiency of Bifidobacterium strains. Therefore, a comprehensive understanding of bifidobacterial glycan metabolism at the strain level is necessary to rationally design probiotic or synbiotic formulations that combine bacterial strains with glycans that match their nutrient preferences. In this study, we systematically reconstructed 66 pathways involved in the utilization of mono-, di-, oligo-, and polysaccharides by analyzing the representation of 565 curated functional roles (catabolic enzymes, transporters, transcriptional regulators) in 2973 non-redundant cultured Bifidobacterium isolates and metagenome-assembled genomes (MAGs). Our analysis uncovered substantial heterogeneity in the predicted glycan utilization capabilities at the species and strain level and revealed the presence of a yet undescribed phenotypically distinct clade within the Bifidobacterium longum species. We also identified Bangladeshi isolates harboring unique gene clusters tentatively implicated in the breakdown of xyloglucan and human milk oligosaccharides. Predicted carbohydrate utilization phenotypes were experimentally characterized and validated. Our large-scale genomic analysis expands the knowledge of carbohydrate metabolism in bifidobacteria and provides a foundation for rationally designing single- or multi-strain probiotic formulations of a given bifidobacterial species as well as synbiotic combinations of bifidobacterial strains matched with their preferred carbohydrate substrates.
2024-08-08 | GSE239955 | GEO
Project description:Extremely thermophilic bacteria from the genus Caldicellulosiruptor can degrade various polysaccharide components of plant cell walls. Previous experimental studies identified a variety of carbohydrate-active enzymes in model species C. saccharolyticus and C.bescii, while prior transcriptomic experiments identified their putative carbohydrate uptake transporters. We investigated the mechanisms of transcriptional regulation of carbohydrate utilization genes using a comparative genomics approach applied to fourteen Caldicellulosiruptor species. The reconstruction of carbohydrate utilization regulatory network includes the predicted binding sites for 34 mostly local regulators and point to the regulatory mechanisms controlling expression of genes involved in degradation of plant biomass. The Rex and CggR regulons control the central glycolytic and primary redox reactions. The identified transcription factor binding sites and regulons were validated with transcriptomic and transcription start site data for C. bescii grown on cellulose, cellobiose, glucose, xylan, and xylose. The XylR and XynR regulons control xylan-induced transcriptional response of genes involved in degradation of xylan and xylose utilization. The reconstructed regulons informed the carbohydrate utilization reconstruction analysis and improved functional annotations of 51 transporters and 11 catabolic enzymes. Using gene deletion, we confirmed that the shared ATPase component MsmK is essential for growth on oligo- and polysaccharides but not for the utilization of monosaccharides. By elucidating the carbohydrate utilization framework in C. bescii, strategies for metabolic engineering can be pursued to optimize yields of bio-based fuels and chemicals from lignocellulose.
2021-02-23 | GSE163472 | GEO
Project description:Extremely thermophilic bacteria from the genus Caldicellulosiruptor can degrade various polysaccharide components of plant cell walls. Previous experimental studies identified a variety of carbohydrate-active enzymes in model species C. saccharolyticus and C.bescii, while prior transcriptomic experiments identified their putative carbohydrate uptake transporters. We investigated the mechanisms of transcriptional regulation of carbohydrate utilization genes using a comparative genomics approach applied to fourteen Caldicellulosiruptor species. The reconstruction of carbohydrate utilization regulatory network includes the predicted binding sites for 34 mostly local regulators and point to the regulatory mechanisms controlling expression of genes involved in degradation of plant biomass. The Rex and CggR regulons control the central glycolytic and primary redox reactions. The identified transcription factor binding sites and regulons were validated with transcriptomic and transcription start site data for C. bescii grown on cellulose, cellobiose, glucose, xylan, and xylose. The XylR and XynR regulons control xylan-induced transcriptional response of genes involved in degradation of xylan and xylose utilization. The reconstructed regulons informed the carbohydrate utilization reconstruction analysis and improved functional annotations of 51 transporters and 11 catabolic enzymes. Using gene deletion, we confirmed that the shared ATPase component MsmK is essential for growth on oligo- and polysaccharides but not for the utilization of monosaccharides. By elucidating the carbohydrate utilization framework in C. bescii, strategies for metabolic engineering can be pursued to optimize yields of bio-based fuels and chemicals from lignocellulose.
2021-02-23 | GSE163473 | GEO
Project description:Comprehensive analysis of genome-wide expression patterns during growth of the hyperthermophilic bacterium Thermotoga maritima on 14 monosaccharide and polysaccharide substrates was undertaken with the goal of proposing carbohydrate specificities for transport systems and putative transcriptional regulators. Saccharide-induced regulons were predicted through the complementary use of comparative genomics, mixed-model analysis of genome-wide microarray expression data, and examination of upstream sequence patterns. The results indicate that T. maritima relies extensively on ABC transporters for carbohydrate uptake, many of which are likely controlled by local regulators responsive to either the transport substrate or a key metabolic degradation product. Roles in uptake of specific carbohydrates were suggested for members of the expanded Opp/Dpp family of ABC transporters. In this family, phylogenetic relationships among transport systems revealed patterns of possible duplication and divergence as a strategy for the evolution of new uptake capabilities. The presence of GC-rich hairpin sequences between substrate-binding proteins and other components of Opp/Dpp family transporters offers a possible explanation for differential regulation of transporter subunit genes. Numerous improvements to T. maritima genome annotations were proposed, including the identification of ABC transport systems originally annotated as oligopeptide transporters as candidate transporters for rhamnose, xylose, beta-xylan, and beta-glucans and identification of genes likely to encode proteins missing from current annotations of the pentose phosphate pathway. Beyond the information obtained for T. maritima, the present study illustrates how expression-based strategies can be used for improving genome annotation in other microorganisms, especially those for which genetic systems are unavailable.
| S-EPMC1272978 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2013-08-02 | GSE37483 | GEO
Project description:Transcriptional regulation of plant biomass degradation and carbohydrate utilization genes in Caldicellulosiruptor bescii
| PRJNA686279 | ENA
Project description:Metabolic pathways have traditionally been described in terms of biochemical reactions and metabolites. With the use of structural genomics and systems biology, we generated a three-dimensional reconstruction of the central metabolic network of the bacterium Thermotoga maritima. The network encompassed 478 proteins, of which 120 were determined by experiment and 358 were modeled. Structural analysis revealed that proteins forming the network are dominated by a small number (only 182) of basic shapes (folds) performing diverse but mostly related functions. Most of these folds are already present in the essential core (approximately 30%) of the network, and its expansion by nonessential proteins is achieved with relatively few additional folds. Thus, integration of structural data with networks analysis generates insight into the function, mechanism, and evolution of biological networks.
| S-EPMC2833182 | biostudies-literature