کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2186443 1096059 2009 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A Single Mutation at Residue 25 Populates the Folding Intermediate of E. coli RNase H and Reveals a Highly Dynamic Partially Folded Ensemble
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
A Single Mutation at Residue 25 Populates the Folding Intermediate of E. coli RNase H and Reveals a Highly Dynamic Partially Folded Ensemble
چکیده انگلیسی

Understanding the nature of partially folded intermediates transiently populated during protein folding is important for understanding both protein folding and misfolding. These ephemeral species, however, often elude direct experimental characterization. The well-characterized protein ribonuclease H (RNase H) from Escherichia coli populates an on-pathway intermediate identified in both bulk studies and single-molecule mechanical unfolding experiments. Here, we set out to trap the transient intermediate of RNase H at equilibrium by selectively destabilizing the region of the protein known to be unfolded in this species. Surprisingly, a single change at Ile25 (I25A) resulted in the equilibrium population of the intermediate under near-native conditions. The intermediate was undetectable in a series of heteronuclear single quantum coherences, revealing the dynamic nature of this partially unfolded form on the timescale of NMR detection. This result is in contrast to studies in which the structures of trapped intermediates are solved by NMR, indicating that they are well packed and native-like. The dynamic nature of the RNase H intermediate may be important for its role as an on-pathway, productive species that promotes efficient folding.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 391, Issue 2, 14 August 2009, Pages 461–470
نویسندگان
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