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Bomble, Y. J.

Publications and source records attributed to Bomble, Y. J..

2 recordsLinked to original sources

Bayesian inference of metabolic kinetics from genome-scale multiomics data

Modern biological tools generate a wealth of data on metabolite and protein concentrations that can be used to help inform new strain designs. However, integrating these data sources to generate predictions of steady-state metabolism typically requires a kinetic description of the enzymatic reactions that occur within a cell. Parameterizing these kinetic models from biological data can be computationally difficult, especially as the amount of data increases. Robust methods must also be able to quantify the uncertainty in model parameters as a function of the available data, which can be particularly computationally intensive. The field of Bayesian inference offers a wide range of methods for estimating distributions in parameter uncertainty. However, these techniques are poorly suited to kinetic metabolic modeling due to the complex kinetic rate laws typically employed and the resulting dynamic system that must be solved. In this paper, we employ linear-logarithmic kinetics to simplify the calculation of steady-state flux distributions and enable efficient sampling and variational inference methods. We demonstrate that detailed information on the posterior distribution of kinetic model parameters can be obtained efficiently at a variety of different problem scales, including large-scale kinetic models trained on multiomics datasets. These results allow modern Bayesian machine learning tools to be leveraged in understanding biological data and developing new, efficient strain designs.

systems biology

Comparative Biochemical and Structural Analysis of Novel Cellulose Binding Proteins (Tapirins) from Extremely Thermophilic Caldicellulosiruptor Species

Genomes of extremely thermophilic Caldicellulosiruptor species encode novel cellulose binding proteins, t[a]pirins, located proximate to the type IV pilus locus. Previously, the C-terminal domain of a t[a]pirin (Calkro_0844) from Caldicellulosiruptor kronotskyensis was shown to be structurally unique and have a cellulose binding affinity akin to family 3 carbohydrate binding modules (CBM3). Here, full-length and C-terminal versions of t[a]pirins from Caldicellulosiruptor bescii (Athe_1870), Caldicellulosiruptor hydrothermalis (Calhy_0908), Caldicellulosiruptor kristjanssonii (Calkr_0826), and Caldicellulosiruptor naganoensis (NA10_0869) were produced recombinantly in Escherichia coli and compared to Calkro_0844. All five t[a]pirins bound to microcrystalline cellulose, switchgrass, poplar, filter paper, but not to xylan. Densitometry analysis of bound protein fractions visualized by SDS-PAGE revealed that Calhy_0908 and Calkr_0826 (from weakly cellulolytic species) associated with the cellulose substrates to a greater extent than Athe_1870, Calkro_0844 and NA10_0869 (from strongly cellulolytic species), perhaps to associate closely with biomass to capture glucans released from lignocellulose by cellulases produced in Caldicellulosiruptor communities. Three-dimensional structures of the C-terminal binding regions of Calhy_0908 and Calkr_0826 were closely related to Calkro_0844, despite the fact that their amino acid sequence identities compared to Calkro_0844 were only 16% and 36%, respectively. Unlike the parent strain, C. bescii mutants lacking the t[a]pirin genes did not bind to cellulose following short-term incubation, reinforcing the significance of these proteins in cell association with plant biomass. Given the scarcity of carbohydrates in neutral terrestrial hot springs, t[a]pirins likely help cells scavenge carbohydrates from lignocellulose to support growth and survival of Caldicellulosiruptor species.\n\nImportanceMechanisms by which microorganisms attach to and degrade lignocellulose are important to understand if effective approaches for conversion of plant biomass into fuels and chemicals are to be developed. Caldicellulosiruptor species grow on carbohydrates from lignocellulose at elevated temperatures and have biotechnological significance for that reason. Novel cellulose binding proteins, called t[a]pirins, are involved in the way Caldicellulosiruptor species interact with microcrystalline cellulose and here additional information about the diversity of these proteins across the genus is provided, including three dimensional structural comparisons.

microbiology