1gjz
From Proteopedia
(New page: 200px<br /> <applet load="1gjz" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gjz" /> '''SOLUTION STRUCTURE OF A DIMERIC N-TERMINAL ...) |
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'''SOLUTION STRUCTURE OF A DIMERIC N-TERMINAL FRAGMENT OF HUMAN UBIQUITIN'''<br /> | '''SOLUTION STRUCTURE OF A DIMERIC N-TERMINAL FRAGMENT OF HUMAN UBIQUITIN'''<br /> | ||
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==Overview== | ==Overview== | ||
Previous peptide dissection and kinetic experiments have indicated that in, vitro folding of ubiquitin may proceed via transient species in which, native-like structure has been acquired in the first 45 residues. A, peptide fragment, UQ(1-51), encompassing residues 1 to 51 of ubiquitin was, produced in order to test whether this portion has propensity for, independent self-assembly. Surprisingly, the construct formed a folded, symmetrical dimer that was stabilised by 0.8 M sodium sulphate at 298 K, (the S state). The solution structure of the UQ(1-51) dimer was determined, by multinuclear NMR spectroscopy. Each subunit of UQ(1-51) consists of an, N-terminal beta-hairpin followed by an alpha-helix and a final, beta-strand, with orientations similar to intact ubiquitin. The dimer is, formed by the third beta-strand of one subunit interleaving between the, hairpin and third strand of the other to give a six-stranded beta-sheet, with the two alpha-helices sitting on top. The helix-helix and strand, portions of the dimer interface also mimic related features in the, structure of ubiquitin. The structural specificity of the UQ(1-51) peptide, is tuneable: as the concentration of sodium sulphate is decreased, near-native alternative conformations are populated in slow chemical, exchange. Magnetization transfer experiments were performed to, characterize the various species present in 0.35 M sodium sulphate, namely, the S state and two minor forms. Chemical shift differences suggest that, one minor form is very similar to the S state, while the other experiences, a significant conformational change in the third strand. A segmental, rearrangement of the third strand in one subunit of the S state would, render the dimer asymmetric, accounting for most of our results. Similar, small-scale transitions in proteins are often invoked to explain solvent, exchange at backbone amide proton sites that have an intermediate level of, protection. | Previous peptide dissection and kinetic experiments have indicated that in, vitro folding of ubiquitin may proceed via transient species in which, native-like structure has been acquired in the first 45 residues. A, peptide fragment, UQ(1-51), encompassing residues 1 to 51 of ubiquitin was, produced in order to test whether this portion has propensity for, independent self-assembly. Surprisingly, the construct formed a folded, symmetrical dimer that was stabilised by 0.8 M sodium sulphate at 298 K, (the S state). The solution structure of the UQ(1-51) dimer was determined, by multinuclear NMR spectroscopy. Each subunit of UQ(1-51) consists of an, N-terminal beta-hairpin followed by an alpha-helix and a final, beta-strand, with orientations similar to intact ubiquitin. The dimer is, formed by the third beta-strand of one subunit interleaving between the, hairpin and third strand of the other to give a six-stranded beta-sheet, with the two alpha-helices sitting on top. The helix-helix and strand, portions of the dimer interface also mimic related features in the, structure of ubiquitin. The structural specificity of the UQ(1-51) peptide, is tuneable: as the concentration of sodium sulphate is decreased, near-native alternative conformations are populated in slow chemical, exchange. Magnetization transfer experiments were performed to, characterize the various species present in 0.35 M sodium sulphate, namely, the S state and two minor forms. Chemical shift differences suggest that, one minor form is very similar to the S state, while the other experiences, a significant conformational change in the third strand. A segmental, rearrangement of the third strand in one subunit of the S state would, render the dimer asymmetric, accounting for most of our results. Similar, small-scale transitions in proteins are often invoked to explain solvent, exchange at backbone amide proton sites that have an intermediate level of, protection. | ||
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| + | ==Disease== | ||
| + | Known disease associated with this structure: Cleft palate, isolated OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=191339 191339]] | ||
==About this Structure== | ==About this Structure== | ||
| - | 1GJZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1GJZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GJZ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: ubiquitin]] | [[Category: ubiquitin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 15:54:13 2008'' |
Revision as of 13:54, 15 February 2008
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SOLUTION STRUCTURE OF A DIMERIC N-TERMINAL FRAGMENT OF HUMAN UBIQUITIN
Contents |
Overview
Previous peptide dissection and kinetic experiments have indicated that in, vitro folding of ubiquitin may proceed via transient species in which, native-like structure has been acquired in the first 45 residues. A, peptide fragment, UQ(1-51), encompassing residues 1 to 51 of ubiquitin was, produced in order to test whether this portion has propensity for, independent self-assembly. Surprisingly, the construct formed a folded, symmetrical dimer that was stabilised by 0.8 M sodium sulphate at 298 K, (the S state). The solution structure of the UQ(1-51) dimer was determined, by multinuclear NMR spectroscopy. Each subunit of UQ(1-51) consists of an, N-terminal beta-hairpin followed by an alpha-helix and a final, beta-strand, with orientations similar to intact ubiquitin. The dimer is, formed by the third beta-strand of one subunit interleaving between the, hairpin and third strand of the other to give a six-stranded beta-sheet, with the two alpha-helices sitting on top. The helix-helix and strand, portions of the dimer interface also mimic related features in the, structure of ubiquitin. The structural specificity of the UQ(1-51) peptide, is tuneable: as the concentration of sodium sulphate is decreased, near-native alternative conformations are populated in slow chemical, exchange. Magnetization transfer experiments were performed to, characterize the various species present in 0.35 M sodium sulphate, namely, the S state and two minor forms. Chemical shift differences suggest that, one minor form is very similar to the S state, while the other experiences, a significant conformational change in the third strand. A segmental, rearrangement of the third strand in one subunit of the S state would, render the dimer asymmetric, accounting for most of our results. Similar, small-scale transitions in proteins are often invoked to explain solvent, exchange at backbone amide proton sites that have an intermediate level of, protection.
Disease
Known disease associated with this structure: Cleft palate, isolated OMIM:[191339]
About this Structure
1GJZ is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structure and properties of a dimeric N-terminal fragment of human ubiquitin., Bolton D, Evans PA, Stott K, Broadhurst RW, J Mol Biol. 2001 Dec 7;314(4):773-87. PMID:11733996
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