1yyj
|
The NMR solution structure of a redesigned apocytochrome b562:Rd-apocyt b562
OverviewOverview
Structures of intermediates and transition states in protein folding are, usually characterized by amide hydrogen exchange and protein engineering, methods and interpreted on the basis of the assumption that they have, native-like conformations. We were able to stabilize and determine the, high-resolution structure of a partially unfolded intermediate that exists, after the rate-limiting step of a four-helix bundle protein, Rd-apocyt, b(562), by multidimensional NMR methods. The intermediate has partial, native-like secondary structure and backbone topology, consistent with our, earlier native state hydrogen exchange results. However, non-native, hydrophobic interactions exist throughout the structure. These and other, results in the literature suggest that non-native hydrophobic interactions, may occur generally in partially folded states. This can alter the, interpretation of mutational protein engineering results in terms of, native-like side chain interactions. In addition, since the intermediate, exists after the rate-limiting step and Rd-apocyt b(562) folds very, rapidly (k(f) approximately 10(4) s(-1)), these results suggest that, non-native hydrophobic interactions, in the absence of topological, misfolding, are repaired too rapidly to slow folding and cause the, accumulation of folding intermediates. More generally, these results, illustrate an approach for determining the high-resolution structure of, folding intermediates.
About this StructureAbout this Structure
1YYJ is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Specific non-native hydrophobic interactions in a hidden folding intermediate: implications for protein folding., Feng H, Takei J, Lipsitz R, Tjandra N, Bai Y, Biochemistry. 2003 Nov 4;42(43):12461-5. PMID:14580191
Page seeded by OCA on Sun Nov 25 04:39:28 2007