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==LEUCINE-272-ALANINE URACIL-DNA GLYCOSYLASE BOUND TO ABASIC SITE-CONTAINING DNA== | |||
<StructureSection load='2ssp' size='340' side='right' caption='[[2ssp]], [[Resolution|resolution]] 2.25Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2ssp]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2SSP OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2SSP FirstGlance]. <br> | |||
==Disease== | </td></tr><tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=AAB:2-DEOXY-RIBOFURANOSE-5-MONOPHOSPHATE'>AAB</scene></td></tr> | ||
[[http://www.uniprot.org/uniprot/UNG_HUMAN UNG_HUMAN]] Defects in UNG are a cause of immunodeficiency with hyper-IgM type 5 (HIGM5) [MIM:[http://omim.org/entry/608106 608106]]. A rare immunodeficiency syndrome characterized by normal or elevated serum IgM levels with absence of IgG, IgA, and IgE. It results in a profound susceptibility to bacterial infections.<ref>PMID:12958596</ref><ref>PMID:15967827</ref> | <tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Uridine_nucleosidase Uridine nucleosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.3 3.2.2.3] </span></td></tr> | ||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ssp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ssp OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2ssp RCSB], [http://www.ebi.ac.uk/pdbsum/2ssp PDBsum]</span></td></tr> | |||
<table> | |||
== Disease == | |||
[[http://www.uniprot.org/uniprot/UNG_HUMAN UNG_HUMAN]] Defects in UNG are a cause of immunodeficiency with hyper-IgM type 5 (HIGM5) [MIM:[http://omim.org/entry/608106 608106]]. A rare immunodeficiency syndrome characterized by normal or elevated serum IgM levels with absence of IgG, IgA, and IgE. It results in a profound susceptibility to bacterial infections.<ref>PMID:12958596</ref> <ref>PMID:15967827</ref> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/UNG_HUMAN UNG_HUMAN]] Excises uracil residues from the DNA which can arise as a result of misincorporation of dUMP residues by DNA polymerase or due to deamination of cytosine. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ss/2ssp_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Three high-resolution crystal structures of DNA complexes with wild-type and mutant human uracil-DNA glycosylase (UDG), coupled kinetic characterizations and comparisons with the refined unbound UDG structure help resolve fundamental issues in the initiation of DNA base excision repair (BER): damage detection, nucleotide flipping versus extrahelical nucleotide capture, avoidance of apurinic/apyrimidinic (AP) site toxicity and coupling of damage-specific and damage-general BER steps. Structural and kinetic results suggest that UDG binds, kinks and compresses the DNA backbone with a 'Ser-Pro pinch' and scans the minor groove for damage. Concerted shifts in UDG simultaneously form the catalytically competent active site and induce further compression and kinking of the double-stranded DNA backbone only at uracil and AP sites, where these nucleotides can flip at the phosphate-sugar junction into a complementary specificity pocket. Unexpectedly, UDG binds to AP sites more tightly and more rapidly than to uracil-containing DNA, and thus may protect cells sterically from AP site toxicity. Furthermore, AP-endonuclease, which catalyzes the first damage-general step of BER, enhances UDG activity, most likely by inducing UDG release via shared minor groove contacts and flipped AP site binding. Thus, AP site binding may couple damage-specific and damage-general steps of BER without requiring direct protein-protein interactions. | |||
Base excision repair initiation revealed by crystal structures and binding kinetics of human uracil-DNA glycosylase with DNA.,Parikh SS, Mol CD, Slupphaug G, Bharati S, Krokan HE, Tainer JA EMBO J. 1998 Sep 1;17(17):5214-26. PMID:9724657<ref>PMID:9724657</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[DNA glycosylate|DNA glycosylate]] | *[[DNA glycosylate|DNA glycosylate]] | ||
== References == | |||
== | <references/> | ||
__TOC__ | |||
[[Category: | </StructureSection> | ||
[[Category: Human]] | |||
[[Category: Uridine nucleosidase]] | [[Category: Uridine nucleosidase]] | ||
[[Category: Bharati, S.]] | [[Category: Bharati, S.]] | ||