Glycosyltransferases (GTs) play a central role in nature. They catalyze the transfer of a sugar moiety to a broad range of acceptor substrates. GTs are highly selective enzymes, allowing the recognition of subtle structural differences in the sequences and stereochemistry of their sugar and acceptor substrates. We report here a series of structural snapshots of the reaction center of the retaining glucosyl-3-phosphoglycerate synthase (GpgS). During this sequence of events, we visualize how the enzyme guides the substrates into the reaction center where the glycosyl transfer reaction takes place, and unveil the mechanism of product release, involving multiple conformational changes not only in the substrates/products but also in the enzyme. The structural data are further complemented by metadynamics free-energy calculations, revealing how the equilibrium of loop conformations is modulated along these itineraries. The information reported here represent an important contribution for the understanding of GT enzymes at the molecular level.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.str.2017.05.009 | DOI Listing |
Arch Biochem Biophys
December 2024
The Division of Structural Biology, The Nuffield Department of Medicine, University of Oxford, UK; The Rosalind Franklin Institute, Harwell Campus, Didcot, OX11 0QS, UK. Electronic address:
Multifunctionality, processivity, and thermostability are critical for the cost-effective enzymatic saccharification of non-food plant biomass polymers such as β-glucans, celluloses, and xylans to generate biofuels and other valuable products. We present molecular insights into a processive multifunctional endo-1,3-1,4-β-d-glucanase (Tt_End5A) from the hyperthermophilic bacterium Thermogutta terrifontis. Tt_End5A demonstrated activities against a broad spectrum of β-polysaccharides, including barley glucan, lichenan, carboxymethyl cellulose, regenerated amorphous cellulose (RAC), Avicel, xylan, laminarin, mannan, curdlan, xanthan, and various chromogenic substrates at pH 7 and temperatures ranging from 70 to 80°C.
View Article and Find Full Text PDFMed Image Anal
December 2024
Department of Mathematics, University of California Irvine, USA; Department of Biomedical Engineering, University of California Irvine, USA. Electronic address:
Predicting the infiltration of Glioblastoma (GBM) from medical MRI scans is crucial for understanding tumor growth dynamics and designing personalized radiotherapy treatment plans. Mathematical models of GBM growth can complement the data in the prediction of spatial distributions of tumor cells. However, this requires estimating patient-specific parameters of the model from clinical data, which is a challenging inverse problem due to limited temporal data and the limited time between imaging and diagnosis.
View Article and Find Full Text PDFChaos
December 2024
Department of Atomic Physics, Eötvös Loránd University, 1117 Pázmány Péter sétány 1A, Budapest, Hungary.
We investigate how the magnetic structures of the plasma change in a large aspect ratio tokamak perturbed by an ergodic magnetic limiter, when a system parameter is non-adiabatically varied in time. We model such a scenario by considering the Ullmann-Caldas nontwist map, where we introduce an explicit time-dependence to the ratio of the limiter and plasma currents. We apply the tools developed recently in the field of chaotic Hamiltonian systems subjected to parameter drift.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA.
We have performed a data science study of Monte Carlo (MC) simulation trajectories to understand factors that can accelerate the formation of zeolite nanoporous crystals, a process that can take days or even weeks. In previous work, MC simulations predicted and experiments confirmed that using a secondary organic structure-directing agent (OSDA) accelerates the crystallization of all-silica LTA zeolite, with experiments finding a three-fold speedup [Bores et al., Phys.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Bundesanstalt für Materialforschung und Prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
Concrete, a versatile construction material, faces pervasive deterioration due to microbiologically influenced corrosion (MIC) in various applications, including sewer systems, marine engineering, and buildings. MIC is initiated by microbial activities such as involving sulfate-reducing bacteria (SRB), sulfur-oxidizing bacteria (SOB), etc., producing corrosive substances like sulfuric acid.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!