1tlf
From Proteopedia
(New page: 200px<br /> <applet load="1tlf" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tlf, resolution 2.6Å" /> '''UNPRECEDENTED QUATER...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1tlf.gif|left|200px]]<br /> | + | [[Image:1tlf.gif|left|200px]]<br /><applet load="1tlf" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1tlf" size=" | + | |
caption="1tlf, resolution 2.6Å" /> | caption="1tlf, resolution 2.6Å" /> | ||
'''UNPRECEDENTED QUATERNARY STRUCTURE OF E. COLI LAC REPRESSOR CORE TETRAMER: IMPLICATIONS FOR DNA LOOPING'''<br /> | '''UNPRECEDENTED QUATERNARY STRUCTURE OF E. COLI LAC REPRESSOR CORE TETRAMER: IMPLICATIONS FOR DNA LOOPING'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the tryptic core fragment of the lac repressor of | + | The crystal structure of the tryptic core fragment of the lac repressor of Escherichia coli (LacR) complexed with the inducer isopropyl-beta-D-thiogalactoside was determined at 2.6 A resolution. The quaternary structure consists of two dyad-symmetric dimers that are nearly parallel to each other. This structure places all four DNA binding domains of intact LacR on the same side of the tetramer, and results in a deep, V-shaped cleft between the two dimers. Each monomer contributes a carboxyl-terminal helix to an antiparallel four-helix bundle that functions as a tetramerization domain. Some of the side chains whose mutation reduce DNA binding form clusters on a surface near the amino terminus. Placing the structure of the DNA binding domain complexed with operator previously determined by nuclear magnetic resonance onto this surface results in two operators being adjacent and nearly parallel to each other. Structural considerations suggest that the two dimers of LacR may flexibly alter their relative orientation in order to bind to the known varied spacings between two operators. |
==About this Structure== | ==About this Structure== | ||
| - | 1TLF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with EMC and IPT as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1TLF with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb39_1.html lac Repressor]]. Full crystallographic information is available from [http:// | + | 1TLF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=EMC:'>EMC</scene> and <scene name='pdbligand=IPT:'>IPT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1TLF with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb39_1.html lac Repressor]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TLF OCA]. |
==Reference== | ==Reference== | ||
| Line 15: | Line 14: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: lac Repressor]] | [[Category: lac Repressor]] | ||
| - | [[Category: Fischmann, T | + | [[Category: Fischmann, T O.]] |
| - | [[Category: Friedman, A | + | [[Category: Friedman, A M.]] |
| - | [[Category: Steitz, T | + | [[Category: Steitz, T A.]] |
[[Category: EMC]] | [[Category: EMC]] | ||
[[Category: IPT]] | [[Category: IPT]] | ||
[[Category: transcription regulation]] | [[Category: transcription regulation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:14:47 2008'' |
Revision as of 13:14, 21 February 2008
|
UNPRECEDENTED QUATERNARY STRUCTURE OF E. COLI LAC REPRESSOR CORE TETRAMER: IMPLICATIONS FOR DNA LOOPING
Overview
The crystal structure of the tryptic core fragment of the lac repressor of Escherichia coli (LacR) complexed with the inducer isopropyl-beta-D-thiogalactoside was determined at 2.6 A resolution. The quaternary structure consists of two dyad-symmetric dimers that are nearly parallel to each other. This structure places all four DNA binding domains of intact LacR on the same side of the tetramer, and results in a deep, V-shaped cleft between the two dimers. Each monomer contributes a carboxyl-terminal helix to an antiparallel four-helix bundle that functions as a tetramerization domain. Some of the side chains whose mutation reduce DNA binding form clusters on a surface near the amino terminus. Placing the structure of the DNA binding domain complexed with operator previously determined by nuclear magnetic resonance onto this surface results in two operators being adjacent and nearly parallel to each other. Structural considerations suggest that the two dimers of LacR may flexibly alter their relative orientation in order to bind to the known varied spacings between two operators.
About this Structure
1TLF is a Single protein structure of sequence from Escherichia coli with and as ligands. The following page contains interesting information on the relation of 1TLF with [lac Repressor]. Full crystallographic information is available from OCA.
Reference
Crystal structure of lac repressor core tetramer and its implications for DNA looping., Friedman AM, Fischmann TO, Steitz TA, Science. 1995 Jun 23;268(5218):1721-7. PMID:7792597
Page seeded by OCA on Thu Feb 21 15:14:47 2008
