2adm
From Proteopedia
(New page: 200px<br /><applet load="2adm" size="450" color="white" frame="true" align="right" spinBox="true" caption="2adm, resolution 2.6Å" /> '''ADENINE-N6-DNA-METHYL...) |
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| - | [[Image:2adm.jpg|left|200px]]<br /><applet load="2adm" size=" | + | [[Image:2adm.jpg|left|200px]]<br /><applet load="2adm" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2adm, resolution 2.6Å" /> | caption="2adm, resolution 2.6Å" /> | ||
'''ADENINE-N6-DNA-METHYLTRANSFERASE TAQI'''<br /> | '''ADENINE-N6-DNA-METHYLTRANSFERASE TAQI'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structures of the binary complexes of the DNA | + | The crystal structures of the binary complexes of the DNA methyltransferase M.TaqI with the inhibitor Sinefungin and the reaction product S-adenosyl-L-homocysteine were determined, both at 2.6 A resolution. Structural comparison of these binary complexes with the complex formed by M.TaqI and the cofactor S-adenosyl-L-methionine suggests that the key element for molecular recognition of these ligands is the binding of their adenosine part in a pocket, and discrimination between cofactor, reaction product and inhibitor is mediated by different conformations of these molecules; the methionine part of S-adenosyl-L-methionine is located in the binding cleft, whereas the amino acid moieties of Sinefungin and S-adenosyl-L-homocysteine are in a different orientation and interact with the active site amino acid residues 105NPPY108. Dissociation constants for the complexes of M.TaqI with the three ligands were determined spectrofluorometrically. Sinefungin binds more strongly than S-adenosyl-L-homocysteine or S-adenosyl-L-methionine, with KD=0.34 microM, 2.4 microM and 2.0 microM, respectively. |
==About this Structure== | ==About this Structure== | ||
| - | 2ADM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus] with SAM as [http://en.wikipedia.org/wiki/ligand ligand]. This structure | + | 2ADM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus] with <scene name='pdbligand=SAM:'>SAM</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. This structure supersedes the now removed PDB entry 1ADM. Active as [http://en.wikipedia.org/wiki/Site-specific_DNA-methyltransferase_(adenine-specific) Site-specific DNA-methyltransferase (adenine-specific)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.72 2.1.1.72] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ADM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:26:17 2008'' |
Revision as of 14:26, 21 February 2008
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ADENINE-N6-DNA-METHYLTRANSFERASE TAQI
Overview
The crystal structures of the binary complexes of the DNA methyltransferase M.TaqI with the inhibitor Sinefungin and the reaction product S-adenosyl-L-homocysteine were determined, both at 2.6 A resolution. Structural comparison of these binary complexes with the complex formed by M.TaqI and the cofactor S-adenosyl-L-methionine suggests that the key element for molecular recognition of these ligands is the binding of their adenosine part in a pocket, and discrimination between cofactor, reaction product and inhibitor is mediated by different conformations of these molecules; the methionine part of S-adenosyl-L-methionine is located in the binding cleft, whereas the amino acid moieties of Sinefungin and S-adenosyl-L-homocysteine are in a different orientation and interact with the active site amino acid residues 105NPPY108. Dissociation constants for the complexes of M.TaqI with the three ligands were determined spectrofluorometrically. Sinefungin binds more strongly than S-adenosyl-L-homocysteine or S-adenosyl-L-methionine, with KD=0.34 microM, 2.4 microM and 2.0 microM, respectively.
About this Structure
2ADM is a Single protein structure of sequence from Thermus aquaticus with as ligand. This structure supersedes the now removed PDB entry 1ADM. Active as Site-specific DNA-methyltransferase (adenine-specific), with EC number 2.1.1.72 Full crystallographic information is available from OCA.
Reference
Differential binding of S-adenosylmethionine S-adenosylhomocysteine and Sinefungin to the adenine-specific DNA methyltransferase M.TaqI., Schluckebier G, Kozak M, Bleimling N, Weinhold E, Saenger W, J Mol Biol. 1997 Jan 10;265(1):56-67. PMID:8995524
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