1a73
From Proteopedia
(New page: 200px<br /><applet load="1a73" size="450" color="white" frame="true" align="right" spinBox="true" caption="1a73, resolution 1.8Å" /> '''INTRON-ENCODED ENDONU...) |
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| - | [[Image:1a73.gif|left|200px]]<br /><applet load="1a73" size=" | + | [[Image:1a73.gif|left|200px]]<br /><applet load="1a73" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1a73, resolution 1.8Å" /> | caption="1a73, resolution 1.8Å" /> | ||
'''INTRON-ENCODED ENDONUCLEASE I-PPOI COMPLEXED WITH DNA'''<br /> | '''INTRON-ENCODED ENDONUCLEASE I-PPOI COMPLEXED WITH DNA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Homing endonucleases are a diverse collection of proteins that are encoded | + | Homing endonucleases are a diverse collection of proteins that are encoded by genes with mobile, self-splicing introns. They have also been identified in self-splicing inteins (protein introns). These enzymes promote the movement of the DNA sequences that encode them from one chromosome location to another; they do this by making a site-specific double-strand break at a target site in an allele that lacks the corresponding mobile intron. The target sites recognized by these small endonucleases are generally long (14-44 base pairs). Four families of homing endonucleases have been identified, including the LAGLIDADG, the His-Cys box, the GIY-YIG and the H-N-H endonucleases. The first identified His-Cys box homing endonuclease was I-PpoI from the slime mould Physarum polycephalum. Its gene resides in one of only a few nuclear introns known to exhibit genetic mobility. Here we report the structure of the I-PpoI homing endonuclease bound to homing-site DNA determined to 1.8 A resolution. I-PpoI displays an elongated fold of dimensions 25 x 35 x 80 A, with mixed alpha/beta topology. Each I-PpoI monomer contains three antiparallel beta-sheets flanked by two long alpha-helices and a long carboxy-terminal tail, and is stabilized by two bound zinc ions 15 A apart. The enzyme possesses a new zinc-bound fold and endonuclease active site. The structure has been determined in both uncleaved substrate and cleaved product complexes. |
==About this Structure== | ==About this Structure== | ||
| - | 1A73 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Physarum_polycephalum Physarum polycephalum] with ZN and MG as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1A73 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Physarum_polycephalum Physarum polycephalum] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1A73 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Physarum polycephalum]] | [[Category: Physarum polycephalum]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Flick, K | + | [[Category: Flick, K E.]] |
| - | [[Category: Junior, R | + | [[Category: Junior, R J.Monnat.]] |
| - | [[Category: Stoddard, B | + | [[Category: Stoddard, B L.]] |
[[Category: MG]] | [[Category: MG]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
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[[Category: zinc]] | [[Category: zinc]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:41:34 2008'' |
Revision as of 09:41, 21 February 2008
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INTRON-ENCODED ENDONUCLEASE I-PPOI COMPLEXED WITH DNA
Overview
Homing endonucleases are a diverse collection of proteins that are encoded by genes with mobile, self-splicing introns. They have also been identified in self-splicing inteins (protein introns). These enzymes promote the movement of the DNA sequences that encode them from one chromosome location to another; they do this by making a site-specific double-strand break at a target site in an allele that lacks the corresponding mobile intron. The target sites recognized by these small endonucleases are generally long (14-44 base pairs). Four families of homing endonucleases have been identified, including the LAGLIDADG, the His-Cys box, the GIY-YIG and the H-N-H endonucleases. The first identified His-Cys box homing endonuclease was I-PpoI from the slime mould Physarum polycephalum. Its gene resides in one of only a few nuclear introns known to exhibit genetic mobility. Here we report the structure of the I-PpoI homing endonuclease bound to homing-site DNA determined to 1.8 A resolution. I-PpoI displays an elongated fold of dimensions 25 x 35 x 80 A, with mixed alpha/beta topology. Each I-PpoI monomer contains three antiparallel beta-sheets flanked by two long alpha-helices and a long carboxy-terminal tail, and is stabilized by two bound zinc ions 15 A apart. The enzyme possesses a new zinc-bound fold and endonuclease active site. The structure has been determined in both uncleaved substrate and cleaved product complexes.
About this Structure
1A73 is a Single protein structure of sequence from Physarum polycephalum with and as ligands. Full crystallographic information is available from OCA.
Reference
DNA binding and cleavage by the nuclear intron-encoded homing endonuclease I-PpoI., Flick KE, Jurica MS, Monnat RJ Jr, Stoddard BL, Nature. 1998 Jul 2;394(6688):96-101. PMID:9665136
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