1bi0: Difference between revisions
New page: left|200px<br /><applet load="1bi0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bi0, resolution 2.3Å" /> '''STRUCTURE OF APO-AND ... |
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[[Image:1bi0.gif|left|200px]]<br /><applet load="1bi0" size=" | [[Image:1bi0.gif|left|200px]]<br /><applet load="1bi0" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1bi0, resolution 2.3Å" /> | caption="1bi0, resolution 2.3Å" /> | ||
'''STRUCTURE OF APO-AND HOLO-DIPHTHERIA TOXIN REPRESSOR'''<br /> | '''STRUCTURE OF APO-AND HOLO-DIPHTHERIA TOXIN REPRESSOR'''<br /> | ||
==Overview== | ==Overview== | ||
The diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae is | The diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae is a divalent metal-activated repressor of chromosomal genes that encode proteins responsible for siderophore-mediated iron uptake and also of the gene of certain corynebacteriophages that encodes diphtheria toxin. DtxR consists of two 25.3-kDa three-domain subunits and is a member of a family of related repressor proteins in several Gram-positive bacterial species, some of which are important human pathogens. In this paper, we report on the first high resolution crystal structures of apo-DtxR in two related space groups. In addition, crystal structures of Zn-DtxR were determined in the same two space groups. The resolutions of the structures range from 2.2 to 2.4 A. The four refined models of the apo- and the holo-repressor exhibit quite similar metal binding centers, which do, however, show higher thermal motion in the apo-structures. All four structures reported differ from each other in one important aspect. The N-terminal DNA-binding domain and the last 20 residues of the dimerization domain of each subunit move significantly with respect to the core of the DtxR dimer, which consists of residues 74-120 from both subunits. These results provide the first indication of a conformational change that may occur upon binding of the holo-repressor to DNA. | ||
==About this Structure== | ==About this Structure== | ||
1BI0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Corynebacterium_diphtheriae Corynebacterium diphtheriae] with ZN and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1BI0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Corynebacterium_diphtheriae Corynebacterium diphtheriae] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BI0 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Corynebacterium diphtheriae]] | [[Category: Corynebacterium diphtheriae]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Hol, W | [[Category: Hol, W G.]] | ||
[[Category: Pohl, E.]] | [[Category: Pohl, E.]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
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[[Category: transcription regulation]] | [[Category: transcription regulation]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:55:28 2008'' | ||
Revision as of 12:55, 21 February 2008
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STRUCTURE OF APO-AND HOLO-DIPHTHERIA TOXIN REPRESSOR
OverviewOverview
The diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae is a divalent metal-activated repressor of chromosomal genes that encode proteins responsible for siderophore-mediated iron uptake and also of the gene of certain corynebacteriophages that encodes diphtheria toxin. DtxR consists of two 25.3-kDa three-domain subunits and is a member of a family of related repressor proteins in several Gram-positive bacterial species, some of which are important human pathogens. In this paper, we report on the first high resolution crystal structures of apo-DtxR in two related space groups. In addition, crystal structures of Zn-DtxR were determined in the same two space groups. The resolutions of the structures range from 2.2 to 2.4 A. The four refined models of the apo- and the holo-repressor exhibit quite similar metal binding centers, which do, however, show higher thermal motion in the apo-structures. All four structures reported differ from each other in one important aspect. The N-terminal DNA-binding domain and the last 20 residues of the dimerization domain of each subunit move significantly with respect to the core of the DtxR dimer, which consists of residues 74-120 from both subunits. These results provide the first indication of a conformational change that may occur upon binding of the holo-repressor to DNA.
About this StructureAbout this Structure
1BI0 is a Single protein structure of sequence from Corynebacterium diphtheriae with and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Motion of the DNA-binding domain with respect to the core of the diphtheria toxin repressor (DtxR) revealed in the crystal structures of apo- and holo-DtxR., Pohl E, Holmes RK, Hol WG, J Biol Chem. 1998 Aug 28;273(35):22420-7. PMID:9712865
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