2v6e: Difference between revisions
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==Overview== | ==Overview== | ||
The termini of linear chromosomes are protected by specialized DNA, structures known as telomeres that also facilitate the complete, replication of DNA ends. The simplest type of telomere is a covalently, closed DNA hairpin structure found in linear chromosomes of prokaryotes, and viruses. Bidirectional replication of a chromosome with hairpin, telomeres produces a catenated circular dimer that is subsequently, resolved into unit-length chromosomes by a dedicated DNA, cleavage-rejoining enzyme known as a hairpin telomere resolvase, (protelomerase). Here we report a crystal structure of the protelomerase, TelK from Klebsiella oxytoca phage varphiKO2, in complex with the, palindromic target DNA. The structure shows the TelK dimer destabilizes, base pairing interactions to promote the .. | The termini of linear chromosomes are protected by specialized DNA, structures known as telomeres that also facilitate the complete, replication of DNA ends. The simplest type of telomere is a covalently, closed DNA hairpin structure found in linear chromosomes of prokaryotes, and viruses. Bidirectional replication of a chromosome with hairpin, telomeres produces a catenated circular dimer that is subsequently, resolved into unit-length chromosomes by a dedicated DNA, cleavage-rejoining enzyme known as a hairpin telomere resolvase, (protelomerase). Here we report a crystal structure of the protelomerase, TelK from Klebsiella oxytoca phage varphiKO2, in complex with the, palindromic target DNA. The structure shows the TelK dimer destabilizes, base pairing interactions to promote the refolding of cleaved DNA ends, into two hairpin ends. We propose that the hairpinning reaction is made, effectively irreversible by a unique protein-induced distortion of the DNA, substrate that prevents religation of the cleaved DNA substrate. | ||
==About this Structure== | ==About this Structure== | ||
2V6E is a | 2V6E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Klebsiella_phage_phiko2 Klebsiella phage phiko2] with VO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2V6E OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: resolvase]] | [[Category: resolvase]] | ||
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Revision as of 19:48, 5 November 2007
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PROTELOMERASE TELK COMPLEXED WITH SUBSTRATE DNA
OverviewOverview
The termini of linear chromosomes are protected by specialized DNA, structures known as telomeres that also facilitate the complete, replication of DNA ends. The simplest type of telomere is a covalently, closed DNA hairpin structure found in linear chromosomes of prokaryotes, and viruses. Bidirectional replication of a chromosome with hairpin, telomeres produces a catenated circular dimer that is subsequently, resolved into unit-length chromosomes by a dedicated DNA, cleavage-rejoining enzyme known as a hairpin telomere resolvase, (protelomerase). Here we report a crystal structure of the protelomerase, TelK from Klebsiella oxytoca phage varphiKO2, in complex with the, palindromic target DNA. The structure shows the TelK dimer destabilizes, base pairing interactions to promote the refolding of cleaved DNA ends, into two hairpin ends. We propose that the hairpinning reaction is made, effectively irreversible by a unique protein-induced distortion of the DNA, substrate that prevents religation of the cleaved DNA substrate.
About this StructureAbout this Structure
2V6E is a Single protein structure of sequence from Klebsiella phage phiko2 with VO4 as ligand. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
An Interlocked Dimer of the Protelomerase TelK Distorts DNA Structure for the Formation of Hairpin Telomeres., Aihara H, Huang WM, Ellenberger T, Mol Cell. 2007 Sep 21;27(6):901-13. PMID:17889664
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