2hyf
From Proteopedia
(New page: 200px<br /><applet load="2hyf" size="450" color="white" frame="true" align="right" spinBox="true" caption="2hyf, resolution 2.8Å" /> '''The Structure of apo-...) |
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| - | [[Image:2hyf.gif|left|200px]]<br /><applet load="2hyf" size=" | + | [[Image:2hyf.gif|left|200px]]<br /><applet load="2hyf" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2hyf, resolution 2.8Å" /> | caption="2hyf, resolution 2.8Å" /> | ||
'''The Structure of apo-MntR from Bacillus subtilis, selenomethionine derivative'''<br /> | '''The Structure of apo-MntR from Bacillus subtilis, selenomethionine derivative'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The manganese transport regulator (MntR) from Bacillus subtilis binds | + | The manganese transport regulator (MntR) from Bacillus subtilis binds cognate DNA sequences in response to elevated manganese concentrations. MntR functions as a homodimer that binds two manganese ions per subunit. Metal binding takes place at the interface of the two domains that comprise each MntR subunit: an N-terminal DNA-binding domain and a C-terminal dimerization domain. In order to elucidate the link between metal binding and activation, a crystallographic study of MntR in its metal-free state has been undertaken. Here we describe the structures of the native protein and a selenomethionine-containing variant, solved to 2.8 A. The two structures contain five crystallographically unique subunits of MntR, providing diverse views of the metal-free protein. In apo-MntR, as in the manganese complex, the dimer is formed by dyad-related C-terminal domains that provide a conserved structural core. Similarly, each DNA-binding domain largely retains the folded conformation found in metal bound forms of MntR. However, compared to metal-activated MntR, the DNA-binding domains move substantially with respect to the dimer interface in apo-MntR. Overlays of multiple apo-MntR structures indicate that there is a greater range of positioning allowed between N and C-terminal domains in the metal-free state and that the DNA-binding domains of the dimer are farther apart than in the activated complex. To further investigate the conformation of the DNA-binding domain of apo-MntR, a site-directed spin labeling experiment was performed on a mutant of MntR containing cysteine at residue 6. Consistent with the crystallographic results, EPR spectra of the spin-labeled mutant indicate that tertiary structure is conserved in the presence or absence of bound metals, though slightly greater flexibility is present in inactive forms of MntR. |
==About this Structure== | ==About this Structure== | ||
| - | 2HYF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with SO4 and EPE as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2HYF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=EPE:'>EPE</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HYF OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transcriptional regulator]] | [[Category: transcriptional regulator]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:47:13 2008'' |
Revision as of 15:47, 21 February 2008
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The Structure of apo-MntR from Bacillus subtilis, selenomethionine derivative
Overview
The manganese transport regulator (MntR) from Bacillus subtilis binds cognate DNA sequences in response to elevated manganese concentrations. MntR functions as a homodimer that binds two manganese ions per subunit. Metal binding takes place at the interface of the two domains that comprise each MntR subunit: an N-terminal DNA-binding domain and a C-terminal dimerization domain. In order to elucidate the link between metal binding and activation, a crystallographic study of MntR in its metal-free state has been undertaken. Here we describe the structures of the native protein and a selenomethionine-containing variant, solved to 2.8 A. The two structures contain five crystallographically unique subunits of MntR, providing diverse views of the metal-free protein. In apo-MntR, as in the manganese complex, the dimer is formed by dyad-related C-terminal domains that provide a conserved structural core. Similarly, each DNA-binding domain largely retains the folded conformation found in metal bound forms of MntR. However, compared to metal-activated MntR, the DNA-binding domains move substantially with respect to the dimer interface in apo-MntR. Overlays of multiple apo-MntR structures indicate that there is a greater range of positioning allowed between N and C-terminal domains in the metal-free state and that the DNA-binding domains of the dimer are farther apart than in the activated complex. To further investigate the conformation of the DNA-binding domain of apo-MntR, a site-directed spin labeling experiment was performed on a mutant of MntR containing cysteine at residue 6. Consistent with the crystallographic results, EPR spectra of the spin-labeled mutant indicate that tertiary structure is conserved in the presence or absence of bound metals, though slightly greater flexibility is present in inactive forms of MntR.
About this Structure
2HYF is a Single protein structure of sequence from Bacillus subtilis with and as ligands. Full crystallographic information is available from OCA.
Reference
The conformations of the manganese transport regulator of Bacillus subtilis in its metal-free state., DeWitt MA, Kliegman JI, Helmann JD, Brennan RG, Farrens DL, Glasfeld A, J Mol Biol. 2007 Feb 2;365(5):1257-65. Epub 2006 Oct 28. PMID:17118401
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