2g1p
From Proteopedia
(New page: 200px<br /><applet load="2g1p" size="450" color="white" frame="true" align="right" spinBox="true" caption="2g1p, resolution 1.89Å" /> '''Structure of E. coli...) |
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| - | [[Image:2g1p.gif|left|200px]]<br /><applet load="2g1p" size=" | + | [[Image:2g1p.gif|left|200px]]<br /><applet load="2g1p" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2g1p, resolution 1.89Å" /> | caption="2g1p, resolution 1.89Å" /> | ||
'''Structure of E. coli DNA adenine methyltransferase (DAM)'''<br /> | '''Structure of E. coli DNA adenine methyltransferase (DAM)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the Escherichia coli Dam | + | The structure of the Escherichia coli Dam DNA-(adenine-N6)-methyltransferase in complex with cognate DNA was determined at 1.89 A resolution in the presence of S-adenosyl-L-homocysteine. DNA recognition and the dynamics of base-flipping were studied by site-directed mutagenesis, DNA methylation kinetics and fluorescence stopped-flow experiments. Our data illustrate the mechanism of coupling of DNA recognition and base-flipping. Contacts to the non-target strand in the second (3') half of the GATC site are established by R124 to the fourth base-pair, and by L122 and P134 to the third base-pair. The aromatic ring of Y119 intercalates into the DNA between the second and third base-pairs, which is essential for base-flipping to occur. Compared to previous published structures of bacteriophage T4 Dam, three major new observations are made in E.coli Dam. (1) The first Gua is recognized by K9, removal of which abrogates the first base-pair recognition. (2) The flipped target Ade binds to the surface of EcoDam in the absence of S-adenosyl-L-methionine, which illustrates a possible intermediate in the base-flipping pathway. (3) The orphaned Thy residue displays structural flexibility by adopting an extrahelical or intrahelical position where it is in contact to N120. |
==About this Structure== | ==About this Structure== | ||
| - | 2G1P 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 SAH and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. 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:// | + | 2G1P 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=SAH:'>SAH</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. 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=2G1P OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bekes, M.]] | [[Category: Bekes, M.]] | ||
[[Category: Cheng, X.]] | [[Category: Cheng, X.]] | ||
| - | [[Category: Horton, J | + | [[Category: Horton, J R.]] |
[[Category: Jeltsch, A.]] | [[Category: Jeltsch, A.]] | ||
[[Category: Liebert, K.]] | [[Category: Liebert, K.]] | ||
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[[Category: dam methylation; gatc recognition; base flipping; bacterial virulence factor]] | [[Category: dam methylation; gatc recognition; base flipping; bacterial virulence factor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:27:30 2008'' |
Revision as of 15:27, 21 February 2008
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Structure of E. coli DNA adenine methyltransferase (DAM)
Overview
The structure of the Escherichia coli Dam DNA-(adenine-N6)-methyltransferase in complex with cognate DNA was determined at 1.89 A resolution in the presence of S-adenosyl-L-homocysteine. DNA recognition and the dynamics of base-flipping were studied by site-directed mutagenesis, DNA methylation kinetics and fluorescence stopped-flow experiments. Our data illustrate the mechanism of coupling of DNA recognition and base-flipping. Contacts to the non-target strand in the second (3') half of the GATC site are established by R124 to the fourth base-pair, and by L122 and P134 to the third base-pair. The aromatic ring of Y119 intercalates into the DNA between the second and third base-pairs, which is essential for base-flipping to occur. Compared to previous published structures of bacteriophage T4 Dam, three major new observations are made in E.coli Dam. (1) The first Gua is recognized by K9, removal of which abrogates the first base-pair recognition. (2) The flipped target Ade binds to the surface of EcoDam in the absence of S-adenosyl-L-methionine, which illustrates a possible intermediate in the base-flipping pathway. (3) The orphaned Thy residue displays structural flexibility by adopting an extrahelical or intrahelical position where it is in contact to N120.
About this Structure
2G1P is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Site-specific DNA-methyltransferase (adenine-specific), with EC number 2.1.1.72 Full crystallographic information is available from OCA.
Reference
Structure and substrate recognition of the Escherichia coli DNA adenine methyltransferase., Horton JR, Liebert K, Bekes M, Jeltsch A, Cheng X, J Mol Biol. 2006 Apr 28;358(2):559-70. Epub 2006 Feb 28. PMID:16524590
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