1f5t: Difference between revisions
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'''DIPHTHERIA TOX REPRESSOR (C102D MUTANT) COMPLEXED WITH NICKEL AND DTXR CONSENSUS BINDING SEQUENCE''' | {{Structure | ||
|PDB= 1f5t |SIZE=350|CAPTION= <scene name='initialview01'>1f5t</scene>, resolution 3.00Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=NI:NICKEL (II) ION'>NI</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''DIPHTHERIA TOX REPRESSOR (C102D MUTANT) COMPLEXED WITH NICKEL AND DTXR CONSENSUS BINDING SEQUENCE''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1F5T is a [ | 1F5T is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Corynebacterium_diphtheriae Corynebacterium diphtheriae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F5T OCA]. | ||
==Reference== | ==Reference== | ||
Methyl groups of thymine bases are important for nucleic acid recognition by DtxR., Chen CS, White A, Love J, Murphy JR, Ringe D, Biochemistry. 2000 Aug 29;39(34):10397-407. PMID:[http:// | Methyl groups of thymine bases are important for nucleic acid recognition by DtxR., Chen CS, White A, Love J, Murphy JR, Ringe D, Biochemistry. 2000 Aug 29;39(34):10397-407. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10956029 10956029] | ||
[[Category: Corynebacterium diphtheriae]] | [[Category: Corynebacterium diphtheriae]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: transcription regulator]] | [[Category: transcription regulator]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:04:50 2008'' | ||
Revision as of 12:04, 20 March 2008
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DIPHTHERIA TOX REPRESSOR (C102D MUTANT) COMPLEXED WITH NICKEL AND DTXR CONSENSUS BINDING SEQUENCE
OverviewOverview
The expression of diphtheria toxin is controlled by the diphtheria toxin repressor (DtxR). Under conditions of high iron concentration, DtxR binds the tox operator to inhibit transcription. To study how DNA binding specificity is achieved by this repressor, we solved the crystal structure of the nickel(II) activated DtxR(C102D) mutant complexed with a 43mer DNA duplex containing the DtxR consensus binding sequence. Structural analysis of this complex and comparison with a previously determined DtxR(C102D)-Ni(II)-tox operator ternary complex revealed unusual van der Waals interactions between Ser37/Pro39 of the repressor helix-turn-helix (HTH) motif and the methyl groups of specific thymine bases in the consensus binding sequence. Gel mobility shift assays utilizing deoxyuridine modified duplex DNA probes proved the importance of these interactions: the four methyl groups shown to interact with Ser37/Pro39 in the crystal structure contribute a total of 3.4 kcal/mol to binding energy. Thus, in addition to making base-specific hydrogen-bonding interactions to the DNA through its Gln43 residue, DtxR also recognizes methyl groups at certain positions in the DNA sequence with its Ser37 and Pro39 side chains, to achieve binding specificity toward its cognate operator sequences.
About this StructureAbout this Structure
1F5T is a Single protein structure of sequence from Corynebacterium diphtheriae. Full crystallographic information is available from OCA.
ReferenceReference
Methyl groups of thymine bases are important for nucleic acid recognition by DtxR., Chen CS, White A, Love J, Murphy JR, Ringe D, Biochemistry. 2000 Aug 29;39(34):10397-407. PMID:10956029
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