1tmz
From Proteopedia
(New page: 200px<br /><applet load="1tmz" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tmz" /> '''TMZIP: A CHIMERIC PEPTIDE MODEL OF THE N-TER...) |
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| - | [[Image:1tmz.gif|left|200px]]<br /><applet load="1tmz" size=" | + | [[Image:1tmz.gif|left|200px]]<br /><applet load="1tmz" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''TMZIP: A CHIMERIC PEPTIDE MODEL OF THE N-TERMINUS OF ALPHA TROPOMYOSIN, NMR, 15 STRUCTURES'''<br /> | '''TMZIP: A CHIMERIC PEPTIDE MODEL OF THE N-TERMINUS OF ALPHA TROPOMYOSIN, NMR, 15 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Tropomyosins (TMs) are highly conserved, coiled-coil, actin binding | + | Tropomyosins (TMs) are highly conserved, coiled-coil, actin binding regulatory proteins found in most eukaryotic cells. The amino-terminal domain of 284-residue TMs is among the most conserved and functionally important regions. The first nine residues are proposed to bind to the carboxyl-terminal nine residues to form the "overlap" region between successive TMs, which bind along the actin filament. Here, the structure of the N-terminus of muscle alpha-TM, in a chimeric peptide, TMZip, has been solved using circular dichroism (CD) and two-dimensional proton nuclear magnetic resonance (2D 1H NMR) spectroscopy. Residues 1-14 of TMZip are the first 14 N-terminal residues of rabbit striated alpha-TM, and residues 15-32 of TMZip are the last 18 C-terminal residues of the yeast GCN4 transcription factor. CD measurements show that TMZip forms a two-stranded coiled-coil alpha-helix with an enthalpy of folding of -34 +/- 2 kcal/mol. In 2D1H NMR studies at 15 degrees C, pH 6.4, the peptide exhibits 123 sequential and medium range intrachain NOE cross peaks per chain, characteristic of alpha-helices extending from residue 1 to residue 29, together with 85 long-range NOE cross peaks arising from interchain interactions. The three-dimensional structure of TMZip has been determined using these data plus an additional 509 intrachain constraints per chain. The coiled-coil domain extends to the N-terminus. Amide hydrogen exchange studies, however, suggest that the TM region is less stable than the GCN4 region. The work reported here is the first atomic-resolution structure of any region of TM and it allows insight into the mechanism of the function of the highly conserved N-terminal domain. |
==About this Structure== | ==About this Structure== | ||
| - | 1TMZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http:// | + | 1TMZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TMZ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Rattus norvegicus]] | [[Category: Rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Farid, R | + | [[Category: Farid, R S.]] |
| - | [[Category: Greenfield, N | + | [[Category: Greenfield, N J.]] |
| - | [[Category: Hitchcock-Degregori, S | + | [[Category: Hitchcock-Degregori, S E.]] |
| - | [[Category: Montelione, G | + | [[Category: Montelione, G T.]] |
[[Category: actin-binding]] | [[Category: actin-binding]] | ||
[[Category: alpha-helix coiled-coil dimer]] | [[Category: alpha-helix coiled-coil dimer]] | ||
| Line 26: | Line 26: | ||
[[Category: tropomyosin]] | [[Category: tropomyosin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:15:16 2008'' |
Revision as of 13:15, 21 February 2008
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TMZIP: A CHIMERIC PEPTIDE MODEL OF THE N-TERMINUS OF ALPHA TROPOMYOSIN, NMR, 15 STRUCTURES
Overview
Tropomyosins (TMs) are highly conserved, coiled-coil, actin binding regulatory proteins found in most eukaryotic cells. The amino-terminal domain of 284-residue TMs is among the most conserved and functionally important regions. The first nine residues are proposed to bind to the carboxyl-terminal nine residues to form the "overlap" region between successive TMs, which bind along the actin filament. Here, the structure of the N-terminus of muscle alpha-TM, in a chimeric peptide, TMZip, has been solved using circular dichroism (CD) and two-dimensional proton nuclear magnetic resonance (2D 1H NMR) spectroscopy. Residues 1-14 of TMZip are the first 14 N-terminal residues of rabbit striated alpha-TM, and residues 15-32 of TMZip are the last 18 C-terminal residues of the yeast GCN4 transcription factor. CD measurements show that TMZip forms a two-stranded coiled-coil alpha-helix with an enthalpy of folding of -34 +/- 2 kcal/mol. In 2D1H NMR studies at 15 degrees C, pH 6.4, the peptide exhibits 123 sequential and medium range intrachain NOE cross peaks per chain, characteristic of alpha-helices extending from residue 1 to residue 29, together with 85 long-range NOE cross peaks arising from interchain interactions. The three-dimensional structure of TMZip has been determined using these data plus an additional 509 intrachain constraints per chain. The coiled-coil domain extends to the N-terminus. Amide hydrogen exchange studies, however, suggest that the TM region is less stable than the GCN4 region. The work reported here is the first atomic-resolution structure of any region of TM and it allows insight into the mechanism of the function of the highly conserved N-terminal domain.
About this Structure
1TMZ is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
The structure of the N-terminus of striated muscle alpha-tropomyosin in a chimeric peptide: nuclear magnetic resonance structure and circular dichroism studies., Greenfield NJ, Montelione GT, Farid RS, Hitchcock-DeGregori SE, Biochemistry. 1998 May 26;37(21):7834-43. PMID:9601044
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