1t2t
From Proteopedia
(New page: 200px<br /><applet load="1t2t" size="450" color="white" frame="true" align="right" spinBox="true" caption="1t2t, resolution 2.50Å" /> '''Crystal structure of...) |
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| - | [[Image:1t2t.gif|left|200px]]<br /><applet load="1t2t" size=" | + | [[Image:1t2t.gif|left|200px]]<br /><applet load="1t2t" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1t2t, resolution 2.50Å" /> | caption="1t2t, resolution 2.50Å" /> | ||
'''Crystal structure of the DNA-binding domain of intron endonuclease I-TevI with operator site'''<br /> | '''Crystal structure of the DNA-binding domain of intron endonuclease I-TevI with operator site'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Customary binding sites of intron-encoded homing endonucleases lie within | + | Customary binding sites of intron-encoded homing endonucleases lie within cognate intronless alleles, at the so-called homing sites. Here, we describe a novel, high-affinity binding site for I-TevI endonuclease, encoded within the group I td intron of phage T4. This site is an operator that overlaps the T4 late promoter, which drives I-TevI expression from within the td intron. I-TevI binds the operator and homing sites with equal affinity, and functions as a transcriptional autorepressor. Distinct sequence and spacing requirements of the catalytic domain result in reduced cleavage activity on operator DNA. Crystallographic studies showed that the overall interactions of the DNA-binding domain with the operator and homing sites are similar, but have some different hydrogen-bonding contacts. We present a model in which the flexibility in protein-DNA interactions allows I-TevI to bind variant intronless alleles to promote intron mobility while facilitating its function in autorepression, and thereby persistence in its host. |
==About this Structure== | ==About this Structure== | ||
| - | 1T2T is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1T2T is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] 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=1T2T OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Belfort, M.]] | [[Category: Belfort, M.]] | ||
| - | [[Category: Boyd, T | + | [[Category: Boyd, T M.]] |
[[Category: Derbyshire, V.]] | [[Category: Derbyshire, V.]] | ||
| - | [[Category: Edgell, D | + | [[Category: Edgell, D R.]] |
[[Category: LaBonne, S.]] | [[Category: LaBonne, S.]] | ||
[[Category: Li, Z.]] | [[Category: Li, Z.]] | ||
| - | [[Category: Roey, P | + | [[Category: Roey, P Van.]] |
| - | [[Category: Shub, D | + | [[Category: Shub, D A.]] |
| - | [[Category: Stanger, M | + | [[Category: Stanger, M J.]] |
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: protein-dna complex]] | [[Category: protein-dna complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:09:15 2008'' |
Revision as of 13:09, 21 February 2008
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Crystal structure of the DNA-binding domain of intron endonuclease I-TevI with operator site
Overview
Customary binding sites of intron-encoded homing endonucleases lie within cognate intronless alleles, at the so-called homing sites. Here, we describe a novel, high-affinity binding site for I-TevI endonuclease, encoded within the group I td intron of phage T4. This site is an operator that overlaps the T4 late promoter, which drives I-TevI expression from within the td intron. I-TevI binds the operator and homing sites with equal affinity, and functions as a transcriptional autorepressor. Distinct sequence and spacing requirements of the catalytic domain result in reduced cleavage activity on operator DNA. Crystallographic studies showed that the overall interactions of the DNA-binding domain with the operator and homing sites are similar, but have some different hydrogen-bonding contacts. We present a model in which the flexibility in protein-DNA interactions allows I-TevI to bind variant intronless alleles to promote intron mobility while facilitating its function in autorepression, and thereby persistence in its host.
About this Structure
1T2T is a Single protein structure of sequence from Bacteriophage t4 with as ligand. Full crystallographic information is available from OCA.
Reference
Intron-encoded homing endonuclease I-TevI also functions as a transcriptional autorepressor., Edgell DR, Derbyshire V, Van Roey P, LaBonne S, Stanger MJ, Li Z, Boyd TM, Shub DA, Belfort M, Nat Struct Mol Biol. 2004 Oct;11(10):936-44. Epub 2004 Sep 7. PMID:15361856
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