1r7m: Difference between revisions

Revision as of 15:47, 21 February 2008

The homing endonuclease I-SceI bound to its DNA recognition region

OverviewOverview

The I-SceI homing endonuclease enhances gene targeting by introducing double-strand breaks at specific chromosomal loci, thereby increasing the recombination frequency. Here, we report the crystal structure of the enzyme complexed to its DNA substrate and Ca(2+) determined at 2.25A resolution. The structure shows the prototypical beta-saddle of LAGLIDADG homing endonucleases that is contributed by two pseudo-symmetric domains. The high specificity of I-SceI is explained by the large number of protein-DNA contacts, many that are made by a long beta-hairpin loop that reaches into the major groove of the DNA. The DNA minor groove is compressed at the catalytic center, bringing the two scissile phosphodiester bonds into close proximity. The protein-Ca(2+)-DNA structure shows the protein bound to its DNA substrate in a pre-reactive state that is defined by the presence of two asymmetric active sites, one of which appears poised to first cleave the DNA bottom strand.

About this StructureAbout this Structure

1R7M is a Single protein structure of sequence from Saccharomyces cerevisiae with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

The crystal structure of the gene targeting homing endonuclease I-SceI reveals the origins of its target site specificity., Moure CM, Gimble FS, Quiocho FA, J Mol Biol. 2003 Dec 5;334(4):685-95. PMID:14636596

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OCA

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-[[Image:1r7m.gif|left|200px]]<br /><applet load="1r7m" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1r7m.gif|left|200px]]<br /><applet load="1r7m" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1r7m, resolution 2.25&Aring;" />
 '''The homing endonuclease I-SceI bound to its DNA recognition region'''<br />
 ==Overview==
-The I-SceI homing endonuclease enhances gene targeting by introducing, double-strand breaks at specific chromosomal loci, thereby increasing the, recombination frequency. Here, we report the crystal structure of the, enzyme complexed to its DNA substrate and Ca(2+) determined at 2.25A, resolution. The structure shows the prototypical beta-saddle of LAGLIDADG, homing endonucleases that is contributed by two pseudo-symmetric domains., The high specificity of I-SceI is explained by the large number of, protein-DNA contacts, many that are made by a long beta-hairpin loop that, reaches into the major groove of the DNA. The DNA minor groove is, compressed at the catalytic center, bringing the two scissile, phosphodiester bonds into close proximity. The protein-Ca(2+)-DNA, structure shows the protein bound to its DNA substrate in a pre-reactive, state that is defined by the presence of two asymmetric active sites, one, of which appears poised to first cleave the DNA bottom strand.
+The I-SceI homing endonuclease enhances gene targeting by introducing double-strand breaks at specific chromosomal loci, thereby increasing the recombination frequency. Here, we report the crystal structure of the enzyme complexed to its DNA substrate and Ca(2+) determined at 2.25A resolution. The structure shows the prototypical beta-saddle of LAGLIDADG homing endonucleases that is contributed by two pseudo-symmetric domains. The high specificity of I-SceI is explained by the large number of protein-DNA contacts, many that are made by a long beta-hairpin loop that reaches into the major groove of the DNA. The DNA minor groove is compressed at the catalytic center, bringing the two scissile phosphodiester bonds into close proximity. The protein-Ca(2+)-DNA structure shows the protein bound to its DNA substrate in a pre-reactive state that is defined by the presence of two asymmetric active sites, one of which appears poised to first cleave the DNA bottom strand.
 ==About this Structure==
-R7M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1R7M OCA].
+R7M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R7M OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Saccharomyces cerevisiae]]
 [[Category: Single protein]]
-[[Category: Gimble, F.S.]]
+[[Category: Gimble, F S.]]
-[[Category: Moure, C.M.]]
+[[Category: Moure, C M.]]
-[[Category: Quiocho, F.A.]]
+[[Category: Quiocho, F A.]]
 [[Category: CA]]
 [[Category: beta-saddle]]
@@ Line 22: / Line 22: @@
 [[Category: protein-dna complex]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:19:59 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:47:56 2008''