1exe
From Proteopedia
(New page: 200px<br /><applet load="1exe" size="450" color="white" frame="true" align="right" spinBox="true" caption="1exe" /> '''SOLUTION STRUCTURE OF A MUTANT OF TRANSCRIPT...) |
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'''SOLUTION STRUCTURE OF A MUTANT OF TRANSCRIPTION FACTOR 1.'''<br /> | '''SOLUTION STRUCTURE OF A MUTANT OF TRANSCRIPTION FACTOR 1.'''<br /> | ||
==Overview== | ==Overview== | ||
| - | An NMR solution structure of a mutant of the homodimer protein | + | An NMR solution structure of a mutant of the homodimer protein transcription factor 1, TF1-G15/I32 (22 kDa), has been solved to atomic resolution, with 23 final structures that converge to an r.m. s.d. of 0.78 A. The overall shape of TF1-G15/I32 remains similar to that of the wild-type protein and other type II DNA-binding proteins. Each monomer has two N-terminal alpha-helices separated by a short loop, followed by a three-stranded beta-sheet, whose extension between the second and third beta-strands forms an antiparallel beta-ribbon arm, leading to a C-terminal third alpha-helix that is severely kinked in the middle. Close examination of the structure of TF1-G15/I32 reveals why it is more stable and binds DNA more tightly than does its wild-type counterpart. The dimeric core, consisting of the N-terminal helices and the beta-sheets, is more tightly packed, and this might be responsible for its increased thermal stability. The DNA-binding domain, composed of the top face of the beta-sheet, the beta-ribbon arms and the C-terminal helices, is little changed from wild-type TF1. Rather, the enhancement in DNA affinity must be due almost exclusively to the creation of an additional DNA-binding site at the side of the dimer by changes affecting helices 1 and 2: helix 2 of TF1-G15/I32 is one residue longer than helix 2 of the wild-type protein, bends inward, and is both translationally and rotationally displaced relative to helix 1. This rearrangement creates a longer, narrower fissure between the V-shaped N-terminal helices and exposes additional positively charged surface at each side of the dimer. |
==About this Structure== | ==About this Structure== | ||
| - | 1EXE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vigna_unguiculata_subsp._cylindrica Vigna unguiculata subsp. cylindrica]. Full crystallographic information is available from [http:// | + | 1EXE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vigna_unguiculata_subsp._cylindrica Vigna unguiculata subsp. cylindrica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EXE OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Vigna unguiculata subsp. cylindrica]] | [[Category: Vigna unguiculata subsp. cylindrica]] | ||
| - | [[Category: Geiduschek, E | + | [[Category: Geiduschek, E P.]] |
| - | [[Category: Kearns, D | + | [[Category: Kearns, D R.]] |
[[Category: Liu, W.]] | [[Category: Liu, W.]] | ||
| - | [[Category: Vu, H | + | [[Category: Vu, H M.]] |
[[Category: beta ribbon arms]] | [[Category: beta ribbon arms]] | ||
[[Category: dna-bending protein]] | [[Category: dna-bending protein]] | ||
[[Category: dna-binding]] | [[Category: dna-binding]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:32:29 2008'' |
Revision as of 10:32, 21 February 2008
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SOLUTION STRUCTURE OF A MUTANT OF TRANSCRIPTION FACTOR 1.
Overview
An NMR solution structure of a mutant of the homodimer protein transcription factor 1, TF1-G15/I32 (22 kDa), has been solved to atomic resolution, with 23 final structures that converge to an r.m. s.d. of 0.78 A. The overall shape of TF1-G15/I32 remains similar to that of the wild-type protein and other type II DNA-binding proteins. Each monomer has two N-terminal alpha-helices separated by a short loop, followed by a three-stranded beta-sheet, whose extension between the second and third beta-strands forms an antiparallel beta-ribbon arm, leading to a C-terminal third alpha-helix that is severely kinked in the middle. Close examination of the structure of TF1-G15/I32 reveals why it is more stable and binds DNA more tightly than does its wild-type counterpart. The dimeric core, consisting of the N-terminal helices and the beta-sheets, is more tightly packed, and this might be responsible for its increased thermal stability. The DNA-binding domain, composed of the top face of the beta-sheet, the beta-ribbon arms and the C-terminal helices, is little changed from wild-type TF1. Rather, the enhancement in DNA affinity must be due almost exclusively to the creation of an additional DNA-binding site at the side of the dimer by changes affecting helices 1 and 2: helix 2 of TF1-G15/I32 is one residue longer than helix 2 of the wild-type protein, bends inward, and is both translationally and rotationally displaced relative to helix 1. This rearrangement creates a longer, narrower fissure between the V-shaped N-terminal helices and exposes additional positively charged surface at each side of the dimer.
About this Structure
1EXE is a Single protein structure of sequence from Vigna unguiculata subsp. cylindrica. Full crystallographic information is available from OCA.
Reference
Solution structure of a mutant of transcription factor 1: implications for enhanced DNA binding., Liu W, Vu HM, Geiduschek EP, Kearns DR, J Mol Biol. 2000 Sep 29;302(4):821-30. PMID:10993726
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