8G2J

Hybrid aspen cellulose synthase-8 bound to UDP-glucose

Summary for 8G2J

• Entry DOI: 10.2210/pdb8g2j/pdb
• EMDB information: 29679
• Related PRD ID: PRD_900016
• Descriptor: Cellulose synthase, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose, URIDINE-5'-DIPHOSPHATE-GLUCOSE, ... (4 entities in total)
• Functional Keywords: cellulose, cell wall, udp, plant protein
• Biological source: Populus tremula x P. tremuloides/Amanita muscaria mixed EST library
• Total number of polymer chains: 3
• Total formula weight: 341707.05

Authors

Verma, P.,Zimmer, J. (deposition date: 2023-02-04, release date: 2023-03-01, Last modification date: 2025-05-14)

Primary citation

Verma, P.,Kwansa, A.L.,Ho, R.,Yingling, Y.G.,Zimmer, J.
Insights into substrate coordination and glycosyl transfer of poplar cellulose synthase-8.
Biorxiv, 2023

PubMed Abstract: Cellulose is an abundant cell wall component of land plants. It is synthesized from UDP-activated glucose molecules by cellulose synthase, a membrane-integrated processive glycosyltransferase. Cellulose synthase couples the elongation of the cellulose polymer with its translocation across the plasma membrane. Here, we present substrate and product-bound cryogenic electron microscopy structures of the homotrimeric cellulose synthase isoform-8 (CesA8) from hybrid aspen (poplar). UDP-glucose binds to a conserved catalytic pocket adjacent to the entrance to a transmembrane channel. The substrate's glucosyl unit is coordinated by conserved residues of the glycosyltransferase domain and amphipathic interface helices. Site-directed mutagenesis of a conserved gating loop capping the active site reveals its critical function for catalytic activity. Molecular dynamics simulations reveal prolonged interactions of the gating loop with the substrate molecule, particularly across its central conserved region. These transient interactions likely facilitate the proper positioning of the substrate molecule for glycosyl transfer and cellulose translocation.

PubMed: 36798277
DOI: 10.1101/2023.02.07.527505

Experimental method

ELECTRON MICROSCOPY (3.3 Å)