1nku
From Proteopedia
(New page: 200px<br /><applet load="1nku" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nku" /> '''NMR Solution Structure of Zinc-binding prote...) |
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'''NMR Solution Structure of Zinc-binding protein 3-methyladenine DNA glycosylase I (TAG)'''<br /> | '''NMR Solution Structure of Zinc-binding protein 3-methyladenine DNA glycosylase I (TAG)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The Escherichia coli 3-methyladenine DNA glycosylase I (TAG) is a DNA | + | The Escherichia coli 3-methyladenine DNA glycosylase I (TAG) is a DNA repair enzyme that excises 3-methyladenine in DNA and is the smallest member of the helix-hairpin-helix (HhH) superfamily of DNA glycosylases. Despite many studies over the last 25 years, there has been no suggestion that TAG was a metalloprotein. However, here we establish by heteronuclear NMR and other spectroscopic methods that TAG binds 1 eq of Zn2+ extremely tightly. A family of refined NMR structures shows that 4 conserved residues contributed from the amino- and carboxyl-terminal regions of TAG (Cys4, His17, His175, and Cys179) form a Zn2+ binding site. The Zn2+ ion serves to tether the otherwise unstructured amino- and carboxyl-terminal regions of TAG. We propose that this unexpected "zinc snap" motif in the TAG family (CX(12-17)HX(approximately 150)HX(3)C) serves to stabilize the HhH domain thereby mimicking the functional role of protein-protein interactions in larger HhH superfamily members. |
==About this Structure== | ==About this Structure== | ||
| - | 1NKU 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]. Active as [http://en.wikipedia.org/wiki/DNA-3-methyladenine_glycosylase_I DNA-3-methyladenine glycosylase I], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.20 3.2.2.20] Full crystallographic information is available from [http:// | + | 1NKU 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]. Active as [http://en.wikipedia.org/wiki/DNA-3-methyladenine_glycosylase_I DNA-3-methyladenine glycosylase I], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.20 3.2.2.20] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NKU OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Cao, C.]] | [[Category: Cao, C.]] | ||
[[Category: Kwon, K.]] | [[Category: Kwon, K.]] | ||
| - | [[Category: Stivers, J | + | [[Category: Stivers, J T.]] |
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:07:08 2008'' |
Revision as of 12:07, 21 February 2008
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NMR Solution Structure of Zinc-binding protein 3-methyladenine DNA glycosylase I (TAG)
Overview
The Escherichia coli 3-methyladenine DNA glycosylase I (TAG) is a DNA repair enzyme that excises 3-methyladenine in DNA and is the smallest member of the helix-hairpin-helix (HhH) superfamily of DNA glycosylases. Despite many studies over the last 25 years, there has been no suggestion that TAG was a metalloprotein. However, here we establish by heteronuclear NMR and other spectroscopic methods that TAG binds 1 eq of Zn2+ extremely tightly. A family of refined NMR structures shows that 4 conserved residues contributed from the amino- and carboxyl-terminal regions of TAG (Cys4, His17, His175, and Cys179) form a Zn2+ binding site. The Zn2+ ion serves to tether the otherwise unstructured amino- and carboxyl-terminal regions of TAG. We propose that this unexpected "zinc snap" motif in the TAG family (CX(12-17)HX(approximately 150)HX(3)C) serves to stabilize the HhH domain thereby mimicking the functional role of protein-protein interactions in larger HhH superfamily members.
About this Structure
1NKU is a Single protein structure of sequence from Escherichia coli with as ligand. Active as DNA-3-methyladenine glycosylase I, with EC number 3.2.2.20 Full crystallographic information is available from OCA.
Reference
A novel zinc snap motif conveys structural stability to 3-methyladenine DNA glycosylase I., Kwon K, Cao C, Stivers JT, J Biol Chem. 2003 May 23;278(21):19442-6. Epub 2003 Mar 24. PMID:12654914
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