+検索条件
-Structure paper
タイトル | Insights into substrate coordination and glycosyl transfer of poplar cellulose synthase-8. |
---|---|
ジャーナル・号・ページ | bioRxiv, Year 2023 |
掲載日 | 2023年2月7日 |
著者 | Preeti Verma / Albert L Kwansa / Ruoya Ho / Yaroslava G Yingling / Jochen Zimmer / |
PubMed 要旨 | 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 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. HIGHLIGHTS: Cryo-EM structures of substrate and product bound poplar cellulose synthase provide insights into substrate selectivitySite directed mutagenesis signifies a critical function of the gating loop for catalysisMolecular dynamics simulations support persistent gating loop - substrate interactionsGating loop helps in positioning the substrate molecule to facilitate cellulose elongationConserved cellulose synthesis substrate binding mechanism across the kingdoms. |
リンク | bioRxiv / PubMed:36798277 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.3 Å |
構造データ | EMDB-29678, PDB-8g27: EMDB-29679, PDB-8g2j: |
化合物 | ChemComp-UDP: ChemComp-UPG: ChemComp-MG: |
由来 |
|
キーワード | PLANT PROTEIN / Transferase / Cellulose / cell wall / UDP |