2oxm: Difference between revisions
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New page: left|200px<br /> <applet load="2oxm" size="450" color="white" frame="true" align="right" spinBox="true" caption="2oxm, resolution 2.5Å" /> '''Crystal structure of... |
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[[Image:2oxm.gif|left|200px]]<br /> | [[Image:2oxm.gif|left|200px]]<br /><applet load="2oxm" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="2oxm" size=" | |||
caption="2oxm, resolution 2.5Å" /> | caption="2oxm, resolution 2.5Å" /> | ||
'''Crystal structure of a UNG2/modified DNA complex that represent a stabilized short-lived extrahelical state in ezymatic DNA base flipping'''<br /> | '''Crystal structure of a UNG2/modified DNA complex that represent a stabilized short-lived extrahelical state in ezymatic DNA base flipping'''<br /> | ||
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==Overview== | ==Overview== | ||
The enzyme uracil DNA glycosylase (UNG) excises unwanted uracil bases in, the genome using an extrahelical base recognition mechanism. Efficient, removal of uracil is essential for prevention of C-to-T transition, mutations arising from cytosine deamination, cytotoxic U*A pairs arising, from incorporation of dUTP in DNA, and for increasing immunoglobulin gene, diversity during the acquired immune response. A central event in all of, these UNG-mediated processes is the singling out of rare U*A or U*G base, pairs in a background of approximately 10(9) T*A or C*G base pairs in the, human genome. Here we establish for the human and Escherichia coli enzymes, that discrimination of thymine and uracil is initiated by thermally, induced opening of T*A and U*A base pairs and not by active participation, of the enzyme. Thus, base-pair dynamics has a critical role in the, genome-wide search for uracil, and may be involved in initial damage, recognition by other DNA repair glycosylases. | The enzyme uracil DNA glycosylase (UNG) excises unwanted uracil bases in, the genome using an extrahelical base recognition mechanism. Efficient, removal of uracil is essential for prevention of C-to-T transition, mutations arising from cytosine deamination, cytotoxic U*A pairs arising, from incorporation of dUTP in DNA, and for increasing immunoglobulin gene, diversity during the acquired immune response. A central event in all of, these UNG-mediated processes is the singling out of rare U*A or U*G base, pairs in a background of approximately 10(9) T*A or C*G base pairs in the, human genome. Here we establish for the human and Escherichia coli enzymes, that discrimination of thymine and uracil is initiated by thermally, induced opening of T*A and U*A base pairs and not by active participation, of the enzyme. Thus, base-pair dynamics has a critical role in the, genome-wide search for uracil, and may be involved in initial damage, recognition by other DNA repair glycosylases. | ||
==About this Structure== | ==About this Structure== | ||
2OXM is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | 2OXM is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Known structural/functional Site: <scene name='pdbsite=AC1:4mf Binding Site For Residue C 27'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OXM OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: uracil dna glycosylase]] | [[Category: uracil dna glycosylase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 12:36:48 2008'' | ||
