7NMC

Crystal structure of beta-2-microglobulin D76E mutant

これはPDB形式変換不可エントリーです。

7NMC の概要

• エントリーDOI: 10.2210/pdb7nmc/pdb
• 分子名称: Beta-2-microglobulin, GLYCEROL, TRIETHYLENE GLYCOL, ... (4 entities in total)
• 機能のキーワード: major histocompatibility complex class 1, beta-2-microglobulin, mutant, d76e, immune system
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 12227.74

構造登録者

Guthertz, N. (登録日: 2021-02-23, 公開日: 2022-08-03, 最終更新日: 2024-10-23)

主引用文献

Guthertz, N.,van der Kant, R.,Martinez, R.M.,Xu, Y.,Trinh, C.,Iorga, B.I.,Rousseau, F.,Schymkowitz, J.,Brockwell, D.J.,Radford, S.E.
The effect of mutation on an aggregation-prone protein: An in vivo, in vitro, and in silico analysis.
Proc.Natl.Acad.Sci.USA, 119:e2200468119-e2200468119, 2022

PubMed Abstract: Aggregation of initially stably structured proteins is involved in more than 20 human amyloid diseases. Despite intense research, however, how this class of proteins assembles into amyloid fibrils remains poorly understood, principally because of the complex effects of amino acid substitutions on protein stability, solubility, and aggregation propensity. We address this question using β2-microglobulin (β2m) as a model system, focusing on D76N-β2m that is involved in hereditary amyloidosis. This amino acid substitution causes the aggregation-resilient wild-type protein to become highly aggregation prone in vitro, although the mechanism by which this occurs remained elusive. Here, we identify the residues key to protecting β2m from aggregation by coupling aggregation with antibiotic resistance in E. coli using a tripartite β-lactamase assay (TPBLA). By performing saturation mutagenesis at three different sites (D53X-, D76X-, and D98X-β2m) we show that residue 76 has a unique ability to drive β2m aggregation in vivo and in vitro. Using a randomly mutated D76N-β2m variant library, we show that all of the mutations found to improve protein behavior involve residues in a single aggregation-prone region (APR) (residues 60 to 66). Surprisingly, no correlation was found between protein stability and protein aggregation rate or yield, with several mutations in the APR decreasing aggregation without affecting stability. Together, the results demonstrate the power of the TPBLA to develop proteins that are resilient to aggregation and suggest a model for D76N-β2m aggregation involving the formation of long-range couplings between the APR and Asn76 in a nonnative state.

PubMed: 35613051
DOI: 10.1073/pnas.2200468119

実験手法

X-RAY DIFFRACTION (1.2 Å)