1z6r
From Proteopedia
(New page: 200px<br /><applet load="1z6r" size="450" color="white" frame="true" align="right" spinBox="true" caption="1z6r, resolution 2.70Å" /> '''Crystal structure of...) |
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| - | [[Image:1z6r.gif|left|200px]]<br /><applet load="1z6r" size=" | + | [[Image:1z6r.gif|left|200px]]<br /><applet load="1z6r" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1z6r, resolution 2.70Å" /> | caption="1z6r, resolution 2.70Å" /> | ||
'''Crystal structure of Mlc from Escherichia coli'''<br /> | '''Crystal structure of Mlc from Escherichia coli'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Mlc from Escherichia coli is a transcriptional repressor controlling the | + | Mlc from Escherichia coli is a transcriptional repressor controlling the expression of a number of genes encoding enzymes of the phosphotransferase system (PTS), including ptsG and manXYZ, the specific enzyme II for glucose and mannose PTS transporters. In addition, Mlc controls the transcription of malT, the gene of the global activator of the mal regulon. The inactivation of Mlc as a repressor is mediated by binding to an actively transporting PtsG (EIICB(Glc)). Here we report the crystal structure of Mlc at 2.7 A resolution representing the first described structure of an ROK (repressors, open reading frames, and kinases) family protein. Mlc forms stable dimers thus explaining its binding affinity to palindromic operator sites. The N-terminal helix-turn-helix domain of Mlc is stabilized by the amphipathic C-terminal helix implicated earlier in EIICB(Glc) binding. Furthermore, the structure revealed a metal-binding site within the cysteine-rich ROK consensus motif that coordinates a structurally important zinc ion. A strongly reduced repressor activity was observed when two of the zinc-coordinating cysteine residues were exchanged against serine or alanine, demonstrating the role of zinc in Mlc-mediated repressor function. The structures of a putative fructokinase from Bacillus subtilis, the glucokinase from Escherichia coli, and a glucomannokinase from Arthrobacter sp. showed high structural homology to the ROK family part of Mlc. |
==About this Structure== | ==About this Structure== | ||
| - | 1Z6R 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 ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1Z6R 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=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z6R OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transcriptional repressor]] | [[Category: transcriptional repressor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:12:38 2008'' |
Revision as of 14:12, 21 February 2008
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Crystal structure of Mlc from Escherichia coli
Overview
Mlc from Escherichia coli is a transcriptional repressor controlling the expression of a number of genes encoding enzymes of the phosphotransferase system (PTS), including ptsG and manXYZ, the specific enzyme II for glucose and mannose PTS transporters. In addition, Mlc controls the transcription of malT, the gene of the global activator of the mal regulon. The inactivation of Mlc as a repressor is mediated by binding to an actively transporting PtsG (EIICB(Glc)). Here we report the crystal structure of Mlc at 2.7 A resolution representing the first described structure of an ROK (repressors, open reading frames, and kinases) family protein. Mlc forms stable dimers thus explaining its binding affinity to palindromic operator sites. The N-terminal helix-turn-helix domain of Mlc is stabilized by the amphipathic C-terminal helix implicated earlier in EIICB(Glc) binding. Furthermore, the structure revealed a metal-binding site within the cysteine-rich ROK consensus motif that coordinates a structurally important zinc ion. A strongly reduced repressor activity was observed when two of the zinc-coordinating cysteine residues were exchanged against serine or alanine, demonstrating the role of zinc in Mlc-mediated repressor function. The structures of a putative fructokinase from Bacillus subtilis, the glucokinase from Escherichia coli, and a glucomannokinase from Arthrobacter sp. showed high structural homology to the ROK family part of Mlc.
About this Structure
1Z6R is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
The crystal structure of Mlc, a global regulator of sugar metabolism in Escherichia coli., Schiefner A, Gerber K, Seitz S, Welte W, Diederichs K, Boos W, J Biol Chem. 2005 Aug 12;280(32):29073-9. Epub 2005 Jun 1. PMID:15929984
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