Cryo‐EM structure of fission yeast tetrameric α‐mannosidase Ams1. Issue 11 (20th October 2020)

• Record Type: Journal Article
• Authors: Zhang, Jianxiu; Wang, Ying‐Ying; Du, Li‐Lin; Ye, Keqiong
• Is Part Of: FEBS open bio. Volume 10:Issue 11(2020)
• Page Start: 2437
• Page End: 2451
• Publication Date: 2020-10-20
• Subjects: catabolism -- Cryo‐EM structure -- N‐glycoprotein -- selective autophagy -- α‐mannosidase; Molecular biology -- Periodicals; Cytology -- Periodicals; Life sciences -- Periodicals; Biological Science Disciplines -- Periodicals; Molecular Biology -- Periodicals; Cell Biology -- Periodicals; Cytology; Life sciences; Molecular biology; Periodicals; 572.805
• DOI: 10.1002/2211-5463.12988
• Languages: English
• ISSNs: 2211-5463

Abstract

Abstract : Fungal α‐mannosidase Ams1 and its mammalian homolog MAN2C1 hydrolyze terminal α‐linked mannoses in free oligosaccharides released from misfolded glycoproteins or lipid‐linked oligosaccharide donors. Ams1 is transported by selective autophagy into vacuoles. Here, we determine the tetrameric structure of Ams1 from the fission yeast Schizosaccharomyces pombe at 3.2 Å resolution by cryo‐electron microscopy. Distinct from a low resolution structure of S. cerevisiae Ams1, S. pombe Ams1 has a prominent N‐terminal tail that mediates tetramerization and an extra β‐sheet domain. Ams1 shares a conserved active site with other enzymes in glycoside hydrolase family 38, to which Ams1 belongs, but contains extra N‐terminal domains involved in tetramerization. The atomic structure of Ams1 reported here will aid understanding of its enzymatic activity and transport mechanism. Abstract : The α‐mannosidase Ams1 is involved in catabolism of oligosaccharides and is transported from the cytoplasm into vacuoles by selective autophagy pathways in yeasts. The cryo‐EM structure of S. pombe Ams1 determined at 3.2 Å resolution reveals the detailed interactions mediating tetramerization, the configuration of the active site, and the differences with a low‐resolution structure of S. cerevisiae Ams1.