5O44

Crystal structure of unbranched mixed tri-Ubiquitin chain containing K48 and K63 linkages.

5O44 の概要

• エントリーDOI: 10.2210/pdb5o44/pdb
• 分子名称: Ubiquitin, Polyubiquitin-B, SULFATE ION, ... (6 entities in total)
• 機能のキーワード: mixed linkage ubiquitin chain, signaling protein
• 由来する生物種: Musca domestica (House fly); 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 52230.24

構造登録者

Padala, P.,Isupov, M.N.,Wiener, R. (登録日: 2017-05-26, 公開日: 2017-11-08, 最終更新日: 2024-01-17)

主引用文献

Padala, P.,Soudah, N.,Giladi, M.,Haitin, Y.,Isupov, M.N.,Wiener, R.
The Crystal Structure and Conformations of an Unbranched Mixed Tri-Ubiquitin Chain Containing K48 and K63 Linkages.
J. Mol. Biol., 429:3801-3813, 2017

PubMed Abstract: The ability of ubiquitin to function in a wide range of cellular processes is ascribed to its capacity to cause a diverse spectrum of modifications. While a target protein can be modified with monoubiquitin, it can also be modified with ubiquitin chains. The latter include seven types of homotypic chains as well as mixed ubiquitin chains. In a mixed chain, not all the isopeptide bonds are restricted to a specific lysine of ubiquitin, resulting in a chain possessing more than one type of linkage. While structural characterization of homotypic chains has been well elucidated, less is known about mixed chains. Here we present the crystal structure of a mixed tri-ubiquitin chain at 3.1-Å resolution. In the structure, the proximal ubiquitin is connected to the middle ubiquitin via K48 and these two ubiquitins adopt a compact structure as observed in K48 di-ubiquitin. The middle ubiquitin links to the distal ubiquitin via its K63 and these ubiquitins adopt two conformations, suggesting a flexible structure. Using small-angle X-ray scattering, we unexpectedly found differences between the conformational ensembles of the above tri-ubiquitin chains and chains possessing the same linkages but in the reverse order. In addition, cleavage of the K48 linkage by DUB is faster if this linkage is at the distal end. Taken together, our results suggest that in mixed chains, not only the type of the linkages but also their sequence determine the structural and functional properties of the chain.

PubMed: 29111344
DOI: 10.1016/j.jmb.2017.10.027

実験手法

X-RAY DIFFRACTION (3.14 Å)