Project description:The Wood-Ljungdahl pathway in acetogens converts C1 compounds, such as CO2 and CO, into acetyl-CoA. Similarly, the glycine synthase pathway assimilates C1 compounds into glycine. Partial glycine synthase genes are widely conserved in the Wood-Ljungdahl pathway gene cluster but functional relationship between the pathways in autotrophic condition remains unknown. To comprehend, we assembled Clostridium drakei genome (5.7-Mbp) with intact glycine synthase pathway and constructed a genome-scale metabolic model, iSL836, predicting increased metabolic flux rates of the Wood-Ljungdahl pathway and the glycine synthase-reductase associated reactions under autotrophic conditions. Along with the observation of significant transcriptional activation of genes in the pathways, surprisingly, 13C-labeling experiments and enzyme activity assays confirmed the strain synthesizes glycine and converts into acetyl-phosphate. This study suggests the Wood-Ljungdahl and the glycine synthase-reductase pathways convert CO2 into acetyl-CoA and acetyl-phosphate, respectively. In our knowledge, this is the first report on co-utilization of the pathways under autotrophic growth in acetogen.
Project description:rs07-09_bou - catma1-bou - Autotrophic growth acquisition is abolished in the bou mutant in Arabidopsis thaliana. BOU encodes a putative mitochondrial acyl carnitine carrier. bou mutant is blocked at the cotyledon stage. Autotrophic growth of the bou mutant can be achieved with addition of sugar in the medium or in darkness. Moreover, BOU gene expression is activated by light and depends on plant developmental stage. We wish to determine what are the consequences of bou gene mutation at the transcriptome level. We wish to understand whether bou growth arrest is due to the modification of specific genes expression or to a general effect on metabolism at the transition from heterotrophic to autotrophic growth. - Seeds from a heterozygous plants were grown for either 5 or 8 days after germination on synthetic medium (MS/2) without sugar under continuous light. We harvested cotyledon-stage blocked plants (bou phenotype) from three independent Petri dishes and also green seedlings with true leaves and fully developed root (heterozygotes with a wild-type phenotype) . We also grew independently Col-O plants for 5 and 8 days to compare them with the bou mutants. Keywords: gene knock in (transgenic),normal vs disease comparison,time course
Project description:The goal of this experiment was to explore the molecular network of glucose-TOR signaling in Arabidopsis seedling autotrophic transition stage. We used the whole-genome microarrays to detail the global program of gene expression mediated by glucose and TOR.
Project description:Autotrophic conversion of CO2 to value-added biochemicals has received considerable attention for the sustainable route to replace the fossil fuels. Particularly, anaerobic acetogenic bacteria are naturally capable of reducing CO2 or CO to various metabolites. To fully utilize their biosynthetic potential, systemic understanding of the metabolic network with the transcriptional and translational regulation of the corresponding genes is highly demanded. Here, we complete a genome sequence of Eubacterium limosum ATCC8466 in a circular form of 4.4 Mb, followed by integrating genome-scale measurements of its transcriptome and translatome. Interestingly, the transcriptionally abundant genes encoding the Wood-Ljungdahl pathway were regulated at translational level with decreased translation efficiency (TE). To understand the regulation, the primary transcriptome was augmented, which determined 1,458 transcription start sites (TSS) and 1,253 5’-untranslated regions (5′UTR). The data supports that under the autotrophic condition the TE of genes for the Wood-Ljungdahl pathway and the energy conservation system were regulated by 5′UTR secondary structure. In addition, it was illustrated that the strain reallocates protein synthesis and energy economically, focusing more on translation of energy conservation system rather than on carbon metabolism under autotrophic growth. Thus, our results provide potential route for strain engineering to enhance syngas fermenting capacity.