8WLA

Cryo-EM structure of the beta-1,3-glucan synthase FKS1-Rho1 complex

Summary for 8WLA

• Entry DOI: 10.2210/pdb8wla/pdb
• EMDB information: 37614
• Descriptor: GTP-binding protein RHO1, 1,3-beta-glucan synthase component FKS1 (2 entities in total)
• Functional Keywords: membrane protein
• Biological source: Saccharomyces cerevisiae (brewer's yeast); More
• Total number of polymer chains: 2
• Total formula weight: 238265.60

Authors

Li, J.L.,Zhu, A.Q.,Liu, J.X.,Dai, X.L.,Yan, C.Y.,Deng, D.,Wang, X. (deposition date: 2023-09-29, release date: 2025-02-19, Last modification date: 2025-03-12)

Primary citation

Li, J.,Liu, H.,Li, J.,Liu, J.,Dai, X.,Zhu, A.,Xiao, Q.,Qian, W.,Li, H.,Guo, L.,Yan, C.,Deng, D.,Luo, Y.,Wang, X.
Cryo-EM structure of the beta-1,3-glucan synthase FKS1-Rho1 complex.
Nat Commun, 16:2054-2054, 2025

PubMed Abstract: β-1,3 Glucan synthase (GS) is essential for fungal cell wall biosynthesis. The GS holoenzyme comprises the glycosyltransferase FKS1 and its regulatory factor Rho1, a small GTPase. However, the mechanism by which Rho1 activates FKS1 in a GTP-dependent manner remains unclear. Here, we present two cryo-EM structures of FKS1, apo and in complex with Rho1. FKS1 adopts a cellulose synthase-like conformation. The interaction between Rho1 and FKS1 is enhanced in the presence of GTPγS. Rho1 is positioned within a pocket between the glycosyltransferase domain of FKS1 (GT domain) and the transmembrane helix spanning TM7-15. Comparison of the two structures reveals extensive conformational changes within FKS1. These alterations suggest that Rho1's GTP/GDP cycling may act as a molecular pump, promoting a dynamic transition between the resting and active states of FKS1. Notably, Rho1 triggers FKS1 conformational changes that may push the growing glucan chain into FKS1's transmembrane channel, thereby facilitating β-1,3-glucan elongation.

PubMed: 40021629
DOI: 10.1038/s41467-025-57152-7

Experimental method

ELECTRON MICROSCOPY (3.4 Å)