1ZTR

Solution structure of Engrailed homeodomain L16A mutant

1ZTR の概要

• エントリーDOI: 10.2210/pdb1ztr/pdb
• 関連するPDBエントリー: 1ENH
• 分子名称: Segmentation polarity homeobox protein engrailed (1 entity in total)
• 機能のキーワード: engrailed homeodomain, denatured state, protein folding, folding intermediate, mutant, transcription
• 由来する生物種: Drosophila melanogaster (fruit fly)
• 細胞内の位置: Nucleus: P02836
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7409.35

構造登録者

Religa, T.L.,Markson, J.S.,Mayor, U.,Freund, S.M.V.,Fersht, A.R. (登録日: 2005-05-27, 公開日: 2005-10-18, 最終更新日: 2024-05-29)

主引用文献

Religa, T.L.,Markson, J.S.,Mayor, U.,Freund, S.M.,Fersht, A.R.
Solution structure of a protein denatured state and folding intermediate.
Nature, 437:1053-1056, 2005

PubMed Abstract: The most controversial area in protein folding concerns its earliest stages. Questions such as whether there are genuine folding intermediates, and whether the events at the earliest stages are just rearrangements of the denatured state or progress from populated transition states, remain unresolved. The problem is that there is a lack of experimental high-resolution structural information about early folding intermediates and denatured states under conditions that favour folding because competent states spontaneously fold rapidly. Here we have solved directly the solution structure of a true denatured state by nuclear magnetic resonance under conditions that would normally favour folding, and directly studied its equilibrium and kinetic behaviour. We engineered a mutant of Drosophila melanogaster Engrailed homeodomain that folds and unfolds reversibly just by changing ionic strength. At high ionic strength, the mutant L16A is an ultra-fast folding native protein, just like the wild-type protein; however, at physiological ionic strength it is denatured. The denatured state is a well-ordered folding intermediate, poised to fold by docking helices and breaking some non-native interactions. It unfolds relatively progressively with increasingly denaturing conditions, and so superficially resembles a denatured state with properties that vary with conditions. Such ill-defined unfolding is a common feature of early folding intermediate states and accounts for why there are so many controversies about intermediates versus compact denatured states in protein folding.

PubMed: 16222301
DOI: 10.1038/nature04054

実験手法

SOLUTION NMR