1r7m: Difference between revisions

Revision as of 07:11, 3 May 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. 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 Page seeded by OCA on Sat May 3 07:11:04 2008

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OCA

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 [[Image:1r7m.gif|left|200px]]
- {{Structure
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-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1r7m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1r7m OCA], [http://www.ebi.ac.uk/pdbsum/1r7m PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1r7m RCSB]</span>
-}}
 '''The homing endonuclease I-SceI bound to its DNA recognition region'''
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 [[Category: Moure, C M.]]
 [[Category: Quiocho, F A.]]
-[[Category: beta-saddle]]
+[[Category: Beta-saddle]]
-[[Category: endonuclease]]
+[[Category: Endonuclease]]
-[[Category: laglidadg]]
+[[Category: Laglidadg]]
-[[Category: protein-dna complex]]
+[[Category: Protein-dna complex]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 07:11:04 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:24:23 2008''