The LacI family protein GlyR3 co-regulates the celC operon and manB in Clostridium thermocellum

  title={The LacI family protein GlyR3 co-regulates the celC operon and manB in Clostridium thermocellum},
  author={Jinlyung Choi and Dawn M. Klingeman and Steven D. Brown and Chris D. Cox},
  journal={Biotechnology for Biofuels},
BackgroundClostridium thermocellum utilizes a wide variety of free and cellulosomal cellulases and accessory enzymes to hydrolyze polysaccharides present in complex substrates. To date only a few studies have unveiled the details by which the expression of these cellulases are regulated. Recent studies have described the auto regulation of the celC operon and determined that the celC–glyR3–licA gene cluster and nearby manB–celT gene cluster are co-transcribed as polycistronic mRNA.ResultsIn… 

Genome-Wide Transcription Factor DNA Binding Sites and Gene Regulatory Networks in Clostridium thermocellum

The study herein is the first report of a large-scale application of DNA-affinity purification sequencing (DAP-seq) to transcription factors (TFs) from a bacterium, shedding light on the roles of TFs delineated by their regulons, and potentially provides a means to enable rational, advanced genetic engineering of C. thermocellum and other organisms alike toward a desired phenotype.

Genômica funcional de Clostridium thermocellum em diferentes condições de cultivo

The results of this work demonstrated proteins that are essential for the degradation of the biomass, in greater number in samples of cellulose CPP, followed by straw FES, and genes involved in chemotaxis and quorum sensing were found in the highest category of up-regulation in bagasse and straw.

Mannose- and Mannobiose-Specific Responses of the Insect-Associated Cellulolytic Bacterium Streptomyces sp. Strain SirexAA-E

A novel mannose and mannobiose responsive transcriptional regulator, SsManR, is discovered, which selectively regulates three α-1,2-mannosidase-coding genes and also demonstrated that the previously reported cellobiose-responsive repressor, SSCebR, could use mannobose as an effector ligand.

Inducing effects of cellulosic hydrolysate components of lignocellulose on cellulosome synthesis in Clostridium thermocellum

The results indicated that cello‐oligosaccharides played the key roles in inducing the synthesis of the cellulosome, but non‐cellulosic polysaccharides showed no inducing effects.

Utilization of Monosaccharides by Hungateiclostridium thermocellum ATCC 27405 through Adaptive Evolution

Adapt laboratory evolution was applied to train the bacterium in hexose sugars-based media, and genome resequencing was used to detect the genes that got mutated during adaptation period, revealing several mutation events in the genomes of the evolved strains, especially in those responsible for sugar transport and central carbon metabolism.

Unifying themes and distinct features of carbon and nitrogen assimilation by polysaccharide-degrading bacteria: a summary of four model systems

This review summary summarized what has been experimentally determined for CAZyme regulation, production, and export in relation to nitrogen metabolism for two Gram-positive and two gram-negative polysaccharide-degrading bacteria and highlighted the shared and unique features of each, with a focus on in vivo studies, in regard to carbon and nitrogen assimilation.



Induction of the celC operon of Clostridium thermocellum by laminaribiose

The results indicate that GlyR3 is a negative regulator of the celC operon consisting of celC, glyR3, and licA, and inducible by laminaribiose, and indicates that, despite the insolubility of the biomass substrate, regulation of the degradative enzymes can be accomplished through soluble sugars generated by the action of the enzymes.

Co-transcription of the celC gene cluster in Clostridium thermocellum

Results indicate that celC, glyR3, and licA form an operon repressible by GlyR3 and inducible by laminaribiose, signaling the availability of β-1,3 glucan in Clostridium thermocellum.

Clostridium thermocellum cellulase CelT, a family 9 endoglucanase without an Ig-like domain or family 3c carbohydrate-binding module

Immunological analysis indicated that CelT is a catalytic component of the C. thermocellum F1 cellulosome, the first report describing the characterization of a family 9 cellulase without an Ig-like domain or family 3c CBM.

A family 26 mannanase produced by Clostridium thermocellum as a component of the cellulosome contains a domain which is conserved in mannanases from anaerobic fungi.

Results indicate that the N-terminal 130 residues of mature Man26A may constitute a weak mannan-binding domain, but significant identity with a region conserved in the three family 26 mannanases from the anaerobic fungus Piromyces equi.

Clostridium thermocellum cellulosomal genes are regulated by extracytoplasmic polysaccharides via alternative sigma factors

Quantitative real-time RT-PCR measurements revealed three- to 30-fold up-expression of the alternative σ factor genes in the presence of cellulose and xylan, thus connecting their expression to direct detection of their extracellular polysaccharide substrates.

Comparison of transcriptional profiles of Clostridium thermocellum grown on cellobiose and pretreated yellow poplar using RNA-Seq

46 cellulosomal protein-encoding genes, genes for 4 pairs of SigI-RsgI for polysaccharide sensing, 7 cellodextrin ABC transporter genes, and a set of NAD(P)H hydogenase and alcohol dehydrogenase genes were up-regulated for cells growing on PYP compared to cellobiose.

Cellodextrin and Laminaribiose ABC Transporters in Clostridium thermocellum

The sugar specificity of the different binding lipoproteins is consistent with the observed substrate preference of C. thermocellum, in which cellodextrins are assimilated faster than cellobiose.

Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities

New transcriptional and proteomic evidence shows that a functional primary scaffoldin plays a more important role compared to secondary scaffoldins in the proper regulation of CAZyme genes, cellodextrin transport, and other cellular functions.

Structures of carbon catabolite protein A–(HPr-Ser46-P) bound to diverse catabolite response element sites reveal the basis for high-affinity binding to degenerate DNA operators

The structures of the CcpA–(HPr-Ser46-P) complex bound to three different operators are solved and reveal properties that license this protein to function as a global transcription regulator.

The cellulosomes: multienzyme machines for degradation of plant cell wall polysaccharides.

The recently described three-dimensional crystal structure of the cohesin-dockerin heterodimer sheds light on the critical amino acids that contribute to this high-affinity protein-protein interaction.