3KIH

The crystal structures of two fragments truncated from 5-bladed beta-propeller lectin, tachylectin-2 (Lib2-D2-15)

3KIH の概要

• エントリーDOI: 10.2210/pdb3kih/pdb
• 関連するPDBエントリー: 3KIF
• 分子名称: 5-bladed beta-propeller lectin, 2-(acetylamido)-2-deoxy-D-glucono-1,5-lactone (3 entities in total)
• 機能のキーワード: 5-bladed beta-propeller, structural genomics, israel structural proteomics center, ispc, sugar binding protein
• 由来する生物種: synthetic construct
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 54966.87

構造登録者

Dym, O.,Tawfik, D.S.,Yadid, I.,Israel Structural Proteomics Center (ISPC) (登録日: 2009-11-02, 公開日: 2010-04-28, 最終更新日: 2023-11-01)

主引用文献

Yadid, I.,Kirshenbaum, N.,Sharon, M.,Dym, O.,Tawfik, D.S.
Metamorphic proteins mediate evolutionary transitions of structure
Proc.Natl.Acad.Sci.USA, 107:7287-7292, 2010

PubMed Abstract: The primary sequence of proteins usually dictates a single tertiary and quaternary structure. However, certain proteins undergo reversible backbone rearrangements. Such metamorphic proteins provide a means of facilitating the evolution of new folds and architectures. However, because natural folds emerged at the early stages of evolution, the potential role of metamorphic intermediates in mediating evolutionary transitions of structure remains largely unexplored. We evolved a set of new proteins based on approximately 100 amino acid fragments derived from tachylectin-2--a monomeric, 236 amino acids, five-bladed beta-propeller. Their structures reveal a unique pentameric assembly and novel beta-propeller structures. Although identical in sequence, the oligomeric subunits adopt two, or even three, different structures that together enable the pentameric assembly of two propellers connected via a small linker. Most of the subunits adopt a wild-type-like structure within individual five-bladed propellers. However, the bridging subunits exhibit domain swaps and asymmetric strand exchanges that allow them to complete the two propellers and connect them. Thus, the modular and metamorphic nature of these subunits enabled dramatic changes in tertiary and quaternary structure, while maintaining the lectin function. These oligomers therefore comprise putative intermediates via which beta-propellers can evolve from smaller elements. Our data also suggest that the ability of one sequence to equilibrate between different structures can be evolutionary optimized, thus facilitating the emergence of new structures.

PubMed: 20368465
DOI: 10.1073/pnas.0912616107

実験手法

X-RAY DIFFRACTION (2.49 Å)