View source for 6dpi


==Crystal Structure of Bacillus Halodurans Ribonuclease H1 K196A in Complex with an RNA/DNA Hybrid: Reaction in 10 mM Mg2+ and 200 mM Rb+ for 40 s at 21 C==
<StructureSection load='6dpi' size='340' side='right' caption='[[6dpi]], [[Resolution|resolution]] 1.35&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6dpi]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6DPI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6DPI FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=RB:RUBIDIUM+ION'>RB</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] </span></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=6dpi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6dpi OCA], [http://pdbe.org/6dpi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6dpi RCSB], [http://www.ebi.ac.uk/pdbsum/6dpi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6dpi ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/RNH1_BACHD RNH1_BACHD]] Endonuclease that specifically degrades the RNA of RNA-DNA hybrids. 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Catalysis by members of the RNase H superfamily of enzymes is generally believed to require only two Mg(2+) ions that are coordinated by active-site carboxylates. By examining the catalytic process of Bacillus halodurans RNase H1 in crystallo, however, we found that the two canonical Mg(2+) ions and an additional K(+) failed to align the nucleophilic water for RNA cleavage. Substrate alignment and product formation required a second K(+) and a third Mg(2+), which replaced the first K(+) and departed immediately after cleavage. A third transient Mg(2+) has also been observed for DNA synthesis, but in that case it coordinates the leaving group instead of the nucleophile as in the case of the RNase H1 hydrolysis reaction. These transient cations have no contact with the enzymes. Other DNA and RNA enzymes that catalyze consecutive cleavage and strand-transfer reactions in a single active site may similarly require cation trafficking coordinated by the substrate.

Cation trafficking propels RNA hydrolysis.,Samara NL, Yang W Nat Struct Mol Biol. 2018 Aug;25(8):715-721. doi: 10.1038/s41594-018-0099-4. Epub, 2018 Aug 3. PMID:30076410<ref>PMID:30076410</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6dpi" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Ribonuclease H]]
[[Category: Samara, N L]]
[[Category: Yang, W]]
[[Category: Divalent cation]]
[[Category: Double helix]]
[[Category: Hydrolase-rna-dna complex]]
[[Category: In crystallo catalysis]]
[[Category: Metal dependent catalysis]]
[[Category: Monovalent cation]]
[[Category: Protein-rna-dna complex]]
[[Category: Rna hydrolysis]]