CryoSeek II: Cryo-EM analysis of glycofibrils from freshwater reveals well- structured glycans coating linear tetrapeptide repeats

• 成果类型: Article
• 署名作者: Wang, Tongtong; Huang, Wenze; Xu, Kui; Sun, Yitong; Zhang, Qiangfeng Cliff; Yan, Chuangye; Li, Zhangqiang; Yan, Nieng
• 署名单位: Tsinghua University; Shenzhen Medical Academy of Research & Translation (SMART); Shenzhen Bay Laboratory
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14830
• DOI: 10.1073/pnas.2423943122
• 发表日期: 2025-01-07
• 关键词: protein glycosylation; biological roles; amino-acid; glycobiology; principles; lipids

摘要

Despite the recent breakthrough in structure determination and prediction of proteins, the structural investigation of carbohydrates remains a challenge. Here, we report the cryo-EM analysis of a glycofibril found in the freshwater in the Tsinghua Lotus Pond. The fibril, which we name TLP-4, is made of a linear chain of tetrapeptide repeats coated with >4 nm thick glycans. In each repeat, two glycans are O- linked to a 3,4- dihydroxyproline and another glycan attaches to the adjacent Ser or Thr. The fibril structure is entirely maintained through glycan packing. Bioinformatic analysis confirms the conservation of the TLP-4 repeats across species, suggesting the existence of a large number of glycofibrils to be discovered. Our findings not only provide valuable insights into the structural roles of glycans in bio- assemblies but also demonstrate the potential of our recently formulated research strategy of CryoSeek to find bioentities and establish prototypes for structural studies of carbohydrates.