1ob8

<StructureSection load='1ob8' size='340' side='right' caption='[[1ob8]], [[Resolution|resolution]] 1.80&Aring;' scene=''>

<table><tr><td colspan='2'>[[1ob8]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_35091 Atcc 35091]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OB8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1OB8 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ob9|1ob9]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ob8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ob8 OCA], [http://pdbe.org/1ob8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ob8 RCSB], [http://www.ebi.ac.uk/pdbsum/1ob8 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ob8 ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/HJE_SULSO HJE_SULSO]] A structure-specific endonuclease that resolves Holliday junction (HJ) intermediates during genetic recombination. Acts only on 4-way DNA junctions in a sequence non-specific manner; introduces paired nicks in opposing strands 2 bases 3' of the point of strand exchange only on continuous strands of 4-way junction DNA. Cleaves both mobile and immobile junctions.<ref>PMID:10623519</ref> <ref>PMID:10736227</ref> <ref>PMID:15921693</ref>

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== Publication Abstract from PubMed ==

Two archaeal Holliday junction resolving enzymes, Holliday junction cleavage (Hjc) and Holliday junction endonuclease (Hje), have been characterized. Both are members of a nuclease superfamily that includes the type II restriction enzymes, although their DNA cleaving activity is highly specific for four-way junction structure and not nucleic acid sequence. Despite 28% sequence identity, Hje and Hjc cleave junctions with distinct cutting patterns--they cut different strands of a four-way junction, at different distances from the junction centre. We report the high-resolution crystal structure of Hje from Sulfolobus solfataricus. The structure provides a basis to explain the differences in substrate specificity of Hje and Hjc, which result from changes in dimer organization, and suggests a viral origin for the Hje gene. Structural and biochemical data support the modelling of an Hje:DNA junction complex, highlighting a flexible loop that interacts intimately with the junction centre. A highly conserved serine residue on this loop is shown to be essential for the enzyme's activity, suggesting a novel variation of the nuclease active site. The loop may act as a conformational switch, ensuring that the active site is completed only on binding a four-way junction, thus explaining the exquisite specificity of these enzymes.

 

<div class="pdbe-citations 1ob8" style="background-color:#fffaf0;"></div>

[[Category: Atcc 35091]]

[[Category: Bond, C S]]

[[Category: Middleton, C L]]

[[Category: Parker, J L]]

[[Category: Richard, D J]]

[[Category: White, M F]]

[[Category: Archaea]]

[[Category: Thermophile]]