National Natural Science Foundation of China (NSFC)
中国
引用
ジャーナル: Nat Commun / 年: 2025 タイトル: Cryo-EM structure of the β-1,3-glucan synthase FKS1-Rho1 complex. 著者: Jialu Li / Huayi Liu / Jian Li / Juxiu Liu / Xinli Dai / Angqi Zhu / Qingjie Xiao / Wenyu Qian / Honghao Li / Li Guo / Chuangye Yan / Dong Deng / Yunzi Luo / Xiang Wang / 要旨: 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 ...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.