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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4
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pubmed:dateCreated |
1998-3-6
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pubmed:abstractText |
The N-terminal domain, residues 1-56, of the ribosomal protein L9 has been chemically synthesized. The isolated domain is monomeric as judged by analytical ultracentrifugation and concentration-dependent CD. Complete 1H chemical shift assignments were obtained using standard methods. 2D-NMR experiments show that the isolated domain adopts the same structure as seen in the full-length protein. It consists of a three-stranded antiparallel beta-sheet sandwiched between two helixes. Thermal and urea unfolding transitions are cooperative, and the unfolding curves generated from different experimental techniques, 1D-NMR, far-UV CD, near-UV CD, and fluorescence, are superimposable. These results suggest that the protein folds by a two-state mechanism. The thermal midpoint of folding is 77 +/- 2 degrees C at pD 8.0, and the domain has a delta G degree folding = 2.8 +/- 0.8 kcal/mol at 40 degrees C, pH 7.0. Near the thermal midpoint of the unfolding transition, the 1D-NMR peaks are significantly broadened, indicating that folding is occurring on the intermediate exchange time scale. The rate of folding was determined by fitting the NMR spectra to a two-state chemical exchange model. Similar folding rates were measured for Phe 5, located in the first beta-strand, and for Tyr 25, located in the short helix between strands two and three. The domain folds extremely rapidly with a folding rate constant of 2000 s-1 near the midpoint of the equilibrium thermal unfolding transition.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Ribosomal Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Urea,
http://linkedlifedata.com/resource/pubmed/chemical/ribosomal protein L9
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
27
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pubmed:volume |
37
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1025-32
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:9454593-Amino Acid Sequence,
pubmed-meshheading:9454593-Bacterial Proteins,
pubmed-meshheading:9454593-Centrifugation, Isopycnic,
pubmed-meshheading:9454593-Circular Dichroism,
pubmed-meshheading:9454593-Geobacillus stearothermophilus,
pubmed-meshheading:9454593-Hot Temperature,
pubmed-meshheading:9454593-Models, Chemical,
pubmed-meshheading:9454593-Molecular Sequence Data,
pubmed-meshheading:9454593-Nuclear Magnetic Resonance, Biomolecular,
pubmed-meshheading:9454593-Peptide Fragments,
pubmed-meshheading:9454593-Protein Denaturation,
pubmed-meshheading:9454593-Protein Folding,
pubmed-meshheading:9454593-Protein Structure, Secondary,
pubmed-meshheading:9454593-Ribosomal Proteins,
pubmed-meshheading:9454593-Urea
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pubmed:year |
1998
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pubmed:articleTitle |
Structure and stability of the N-terminal domain of the ribosomal protein L9: evidence for rapid two-state folding.
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pubmed:affiliation |
Department of Chemistry, State University of New York, Stony Brook 11794-3400, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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