2O7A

T4 lysozyme C-terminal fragment

2O7A の概要

• エントリーDOI: 10.2210/pdb2o7a/pdb
• 関連するPDBエントリー: 2O4W 2O79
• 分子名称: Lysozyme, ACETATE ION, CHLORIDE ION, ... (4 entities in total)
• 機能のキーワード: protein folding, protein stability, lysozyme, circular permutant, hydrolase
• 由来する生物種: Enterobacteria phage T4; 詳細
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14132.50

構造登録者

Echols, N.,Kwon, E.,Marqusee, S.M.,Alber, T. (登録日: 2006-12-10, 公開日: 2007-04-10, 最終更新日: 2023-08-30)

主引用文献

Cellitti, J.,Llinas, M.,Echols, N.,Shank, E.A.,Gillespie, B.,Kwon, E.,Crowder, S.M.,Dahlquist, F.W.,Alber, T.,Marqusee, S.
Exploring subdomain cooperativity in T4 lysozyme I: Structural and energetic studies of a circular permutant and protein fragment.
Protein Sci., 16:842-851, 2007

PubMed Abstract: Small proteins are generally observed to fold in an apparent two-state manner. Recently, however, more sensitive techniques have demonstrated that even seemingly single-domain proteins are actually made up of smaller subdomains. T4 lysozyme is one such protein. We explored the relative autonomy of its two individual subdomains and their contribution to the overall stability of T4 lysozyme by examining a circular permutation (CP13*) that relocates the N-terminal A-helix, creating subdomains that are contiguous in sequence. By determining the high-resolution structure of CP13* and characterizing its energy landscape using native state hydrogen exchange (NSHX), we show that connectivity between the subdomains is an important determinant of the energetic cooperativity but not structural integrity of the protein. The circular permutation results in a protein more easily able to populate a partially unfolded form in which the C-terminal subdomain is folded and the N-terminal subdomain is unfolded. We also created a fragment model of this intermediate and demonstrate using X-ray crystallography that its structure is identical to the corresponding residues in the full-length protein with the exception of a small network of hydrophobic interactions. In sum, we conclude that the C-terminal subdomain dominates the energetics of T4 lysozyme folding, and the A-helix serves an important role in coupling the two subdomains.

PubMed: 17400926
DOI: 10.1110/ps.062628607

実験手法

X-RAY DIFFRACTION (0.84 Å)