9IKK

Cryo-EM structure of TLP-1b

9IKK の概要

• エントリーDOI: 10.2210/pdb9ikk/pdb
• EMDBエントリー: 60657
• 分子名称: TLP-2 (1 entity in total)
• 機能のキーワード: fibril, protein fibril
• 由来する生物種: algae metagenome
• タンパク質・核酸の鎖数: 16
• 化学式量合計: 404631.84

構造登録者

Yan, N.,Yan, C.,Li, Z.,Wang, T. (登録日: 2024-06-27, 公開日: 2024-11-13, 最終更新日: 2025-08-13)

主引用文献

Wang, T.,Li, Z.,Xu, K.,Huang, W.,Huang, G.,Zhang, Q.C.,Yan, N.
CryoSeek: A strategy for bioentity discovery using cryoelectron microscopy.
Proc.Natl.Acad.Sci.USA, 121:e2417046121-e2417046121, 2024

PubMed Abstract: Structural biology is experiencing a paradigm shift from targeted structural determination to structure-guided discovery of previously uncharacterized bioentities. We employed cryoelectron microscopy (cryo-EM) to analyze filtered water samples collected from the Tsinghua Lotus Pond. Here, we report the structural determination and characterization of two highly similar helical fibrils, named TLP-1a and TLP-1b, each approximately 8 nm in diameter with a 15-Å wide tunnel. These fibrils are assembled from a similar protein protomer, whose structure was conveniently automodeled in CryoNet. The protomer structure does not match any available experimental structures, but shares the same fold as many predicted structures of unknown functions. The amino-terminal β strand of protomer n + 4 inserts into a cleft in protomer n to complete an immunoglobulin (Ig)-like domain. This packing mechanism, known as donor-strand exchange (DSE), has been observed in several bacterial pilus assemblies, wherein the donor is protomer n + 1. Despite distinct shape and thickness, this reminiscence suggests that TLP-1a/b fibrils may represent uncharacterized bacterial pili. Our study demonstrates an emerging paradigm in structural biology, where high-resolution structural determination precedes and drives the identification and characterization of completely unknown objects.

PubMed: 39382995
DOI: 10.1073/pnas.2417046121

実験手法

ELECTRON MICROSCOPY (3.51 Å)