1yyx
From Proteopedia
(New page: 200px<br /><applet load="1yyx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1yyx" /> '''The solution structure of a redesigned apocy...) |
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| - | [[Image:1yyx.gif|left|200px]]<br /><applet load="1yyx" size=" | + | [[Image:1yyx.gif|left|200px]]<br /><applet load="1yyx" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1yyx" /> | caption="1yyx" /> | ||
'''The solution structure of a redesigned apocytochrome B562 (Rd-apocyt b562) at 2.8M urea'''<br /> | '''The solution structure of a redesigned apocytochrome B562 (Rd-apocyt b562) at 2.8M urea'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The absence of detectable kinetic and equilibrium folding intermediates by | + | The absence of detectable kinetic and equilibrium folding intermediates by optical probes is commonly taken to indicate that protein folding is a two-state process. However, for some small proteins with apparent two-state behavior, unfolding intermediates have been identified in native-state hydrogen exchange or kinetic unfolding experiments monitored by nuclear magnetic resonance. Rd-apocytochrome b(562), a four-helix bundle, is one such protein. Here, we found another unfolding intermediate for Rd-apocytochrome b(562). It is based on a cooperative transition of (15)N chemical shifts of amide protons as a function of urea concentrations before the global unfolding. We have solved the high-resolution structure of the protein at 2.8 M urea, which is after this cooperative transition but before the global unfolding. All four helices remained intact, but a number of hydrophobic core residues repacked. This intermediate provides a possible structural interpretation for the kinetic unfolding intermediates observed using nuclear magnetic resonance methods for several proteins and has important implications for theoretical studies of protein folding. |
==About this Structure== | ==About this Structure== | ||
| - | 1YYX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | + | 1YYX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YYX OCA]. |
==Reference== | ==Reference== | ||
Detection and structure determination of an equilibrium unfolding intermediate of Rd-apocytochrome b562: native fold with non-native hydrophobic interactions., Feng H, Vu ND, Bai Y, J Mol Biol. 2004 Nov 5;343(5):1477-85. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15491625 15491625] | Detection and structure determination of an equilibrium unfolding intermediate of Rd-apocytochrome b562: native fold with non-native hydrophobic interactions., Feng H, Vu ND, Bai Y, J Mol Biol. 2004 Nov 5;343(5):1477-85. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15491625 15491625] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: BSGC, Berkeley | + | [[Category: BSGC, Berkeley Structural Genomics Center.]] |
[[Category: Bai, Y.]] | [[Category: Bai, Y.]] | ||
[[Category: Feng, H.]] | [[Category: Feng, H.]] | ||
| Line 25: | Line 25: | ||
[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:10:32 2008'' |
Revision as of 14:10, 21 February 2008
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The solution structure of a redesigned apocytochrome B562 (Rd-apocyt b562) at 2.8M urea
Overview
The absence of detectable kinetic and equilibrium folding intermediates by optical probes is commonly taken to indicate that protein folding is a two-state process. However, for some small proteins with apparent two-state behavior, unfolding intermediates have been identified in native-state hydrogen exchange or kinetic unfolding experiments monitored by nuclear magnetic resonance. Rd-apocytochrome b(562), a four-helix bundle, is one such protein. Here, we found another unfolding intermediate for Rd-apocytochrome b(562). It is based on a cooperative transition of (15)N chemical shifts of amide protons as a function of urea concentrations before the global unfolding. We have solved the high-resolution structure of the protein at 2.8 M urea, which is after this cooperative transition but before the global unfolding. All four helices remained intact, but a number of hydrophobic core residues repacked. This intermediate provides a possible structural interpretation for the kinetic unfolding intermediates observed using nuclear magnetic resonance methods for several proteins and has important implications for theoretical studies of protein folding.
About this Structure
1YYX is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Detection and structure determination of an equilibrium unfolding intermediate of Rd-apocytochrome b562: native fold with non-native hydrophobic interactions., Feng H, Vu ND, Bai Y, J Mol Biol. 2004 Nov 5;343(5):1477-85. PMID:15491625
Page seeded by OCA on Thu Feb 21 16:10:32 2008
