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Biosynthesis of Bacterial Cellulose
Published in Miguel Gama, Paul Gatenholm, Dieter Klemm, Bacterial NanoCellulose, 2016
Inder M. Saxena, R. Malcolm Brown
Although we can debate whether the repeating subunit in the β-1,4-glucan chains in cellulose is glucose or cellobiose, there is no doubt about the two-fold symmetry of these chains. The mechanism by which the adjacent glucose residues assume a 180° rotation with respect to each other in the β-1,4-glucan chains is not clearly understood and a model proposing two UDP-glucose binding sites in the cellulose synthase suggested that this feature of the glucan chains is generated during cellulose synthesis (Saxena et al. 1995). Since then, other proposals have suggested that a dimer of cellulose synthases, each with a single UDP-glucose binding site, may be involved in generating the 180° orientation of adjacent glucose residues, or that a single cellulose synthase with a single UDP-glucose binding site can add glucose residues to the growing end and these residues would then be able to rotate on their own once they have exited the catalytic site (Delmer 1999). Unfortunately the crystallographic structure of cellulose synthase remains to be determined, and in its absence this question remains unanswered.
Polymeric Materials Obtained through Biocatalysis
Published in Severian Dumitriu, Valentin Popa, Polymeric Biomaterials, 2020
Florin Dan Irimie, Csaba Paizs, Monica Ioana Tosa
The canonical model at hand is cellulose synthase (UDP forming), E.C. 2.4.1.12 [5] (Scheme 18.1) [1] responsible for cellulose synthesis. A similar enzyme is cellulose synthase (GDP forming), E.C. 2.4.1.29 [6].
Cellulose, the Main Component of Biomass
Published in Jean-Luc Wertz, Magali Deleu, Séverine Coppée, Aurore Richel, Hemicelluloses and Lignin in Biorefineries, 2017
Jean-Luc Wertz, Magali Deleu, Séverine Coppée, Aurore Richel
The only cellulose synthase substrate is uridine 5′-diphospho-glucose (UDPGlc), which is a nucleotide sugar located in the cytoplasm of many plant and bacterial cells. UDPGlc is thought to bind to an active site of the enzyme on the cytoplasmic face of the plasma membrane.40
A hypothesis for the architecture of plant secondary cell walls, involving liquid crystalline arrays of microtubules in the cortex of the cell
Published in Liquid Crystals, 2021
This follows a long line of descent from the earlier studies of the effect of the mitotic poison, colchicine, which acts by supressing the production of microtubules by the aggregation of tubulin dimers [30]. It shows that the cellulose synthase trajectories can be maintained in the absence of microtubules and indicates that there must be a separate guidance mechanism.