1ri3: Difference between revisions

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[[Image:1ri3.jpg|left|200px]]<br /><applet load="1ri3" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1ri3.jpg|left|200px]]<br /><applet load="1ri3" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1ri3, resolution 2.50Å" />

'''Structure and mechanism of mRNA cap (guanine N-7) methyltransferase'''<br />

==Overview==

A suite of crystal structures is reported for a cellular mRNA cap, (guanine-N7) methyltransferase in complex with AdoMet, AdoHcy, and the cap, guanylate. Superposition of ligand complexes suggests an in-line mechanism, of methyl transfer, albeit without direct contacts between the enzyme and, either the N7 atom of guanine (the attacking nucleophile), the methyl, carbon of AdoMet, or the sulfur of AdoMet/AdoHcy (the leaving group). The, structures indicate that catalysis of cap N7 methylation is accomplished, by optimizing proximity and orientation of the substrates, assisted by a, favorable electrostatic environment. The enzyme-ligand structures, together with new mutational data, fully account for the biochemical, specificity of the cap guanine-N7 methylation reaction, an essential and, defining step of eukaryotic mRNA synthesis.

A suite of crystal structures is reported for a cellular mRNA cap (guanine-N7) methyltransferase in complex with AdoMet, AdoHcy, and the cap guanylate. Superposition of ligand complexes suggests an in-line mechanism of methyl transfer, albeit without direct contacts between the enzyme and either the N7 atom of guanine (the attacking nucleophile), the methyl carbon of AdoMet, or the sulfur of AdoMet/AdoHcy (the leaving group). The structures indicate that catalysis of cap N7 methylation is accomplished by optimizing proximity and orientation of the substrates, assisted by a favorable electrostatic environment. The enzyme-ligand structures, together with new mutational data, fully account for the biochemical specificity of the cap guanine-N7 methylation reaction, an essential and defining step of eukaryotic mRNA synthesis.

==About this Structure==

1RI3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Encephalitozoon_cuniculi Encephalitozoon cuniculi] with SAH as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1RI3 OCA].

1RI3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Encephalitozoon_cuniculi Encephalitozoon cuniculi] with <scene name='pdbligand=SAH:'>SAH</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RI3 OCA].

==Reference==

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[[Category: Fabrega, C.]]

[[Category: Hausmann, S.]]

[[Category: Lima, C.D.]]

[[Category: Lima, C D.]]

[[Category: Shen, V.]]

[[Category: Shuman, S.]]

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[[Category: rna]]

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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:51:07 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1ri3.jpg|left|200px]]<br /><applet load="1ri3" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1ri3.jpg|left|200px]]<br /><applet load="1ri3" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1ri3, resolution 2.50&Aring;" />
 '''Structure and mechanism of mRNA cap (guanine N-7) methyltransferase'''<br />
 ==Overview==
-A suite of crystal structures is reported for a cellular mRNA cap, (guanine-N7) methyltransferase in complex with AdoMet, AdoHcy, and the cap, guanylate. Superposition of ligand complexes suggests an in-line mechanism, of methyl transfer, albeit without direct contacts between the enzyme and, either the N7 atom of guanine (the attacking nucleophile), the methyl, carbon of AdoMet, or the sulfur of AdoMet/AdoHcy (the leaving group). The, structures indicate that catalysis of cap N7 methylation is accomplished, by optimizing proximity and orientation of the substrates, assisted by a, favorable electrostatic environment. The enzyme-ligand structures, together with new mutational data, fully account for the biochemical, specificity of the cap guanine-N7 methylation reaction, an essential and, defining step of eukaryotic mRNA synthesis.
+A suite of crystal structures is reported for a cellular mRNA cap (guanine-N7) methyltransferase in complex with AdoMet, AdoHcy, and the cap guanylate. Superposition of ligand complexes suggests an in-line mechanism of methyl transfer, albeit without direct contacts between the enzyme and either the N7 atom of guanine (the attacking nucleophile), the methyl carbon of AdoMet, or the sulfur of AdoMet/AdoHcy (the leaving group). The structures indicate that catalysis of cap N7 methylation is accomplished by optimizing proximity and orientation of the substrates, assisted by a favorable electrostatic environment. The enzyme-ligand structures, together with new mutational data, fully account for the biochemical specificity of the cap guanine-N7 methylation reaction, an essential and defining step of eukaryotic mRNA synthesis.
 ==About this Structure==
-RI3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Encephalitozoon_cuniculi Encephalitozoon cuniculi] with SAH as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1RI3 OCA].
+RI3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Encephalitozoon_cuniculi Encephalitozoon cuniculi] with <scene name='pdbligand=SAH:'>SAH</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RI3 OCA].
 ==Reference==
@@ Line 15: / Line 15: @@
 [[Category: Fabrega, C.]]
 [[Category: Hausmann, S.]]
-[[Category: Lima, C.D.]]
+[[Category: Lima, C D.]]
 [[Category: Shen, V.]]
 [[Category: Shuman, S.]]
@@ Line 25: / Line 25: @@
 [[Category: rna]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:36:54 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:51:07 2008''