1d9d

<table><tr><td colspan='2'>[[1d9d]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D9D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1D9D FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=C31:2-O-3-AMINOPROPYL+CYTIDINE-5-MONOPHOSPHATE'>C31</scene>, <scene name='pdbligand=U31:2-O-3-AMINOPROPYL+2-DEOXYURIDINE-5-MONOPHOSPHATE'>U31</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] </span></td></tr>

[[https://www.uniprot.org/uniprot/DPO1_ECOLI DPO1_ECOLI]] In addition to polymerase activity, this DNA polymerase exhibits 3' to 5' and 5' to 3' exonuclease activity. It is able to utilize nicked circular duplex DNA as a template and can unwind the parental DNA strand from its template.

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== Publication Abstract from PubMed ==

Nuclease resistance and RNA affinity are key criteria in the search for optimal antisense nucleic acid modifications, but the origins of the various levels of resistance to nuclease degradation conferred by chemical modification of DNA and RNA are currently not understood. The 2'-O-aminopropyl (AP)-RNA modification displays the highest nuclease resistance among all phosphodiester-based analogues and its RNA binding affinity surpasses that of phosphorothioate DNA by 1 degrees C per modified residue. We found that oligodeoxynucleotides containing AP-RNA residues at their 3' ends competitively inhibit the degradation of single-stranded DNA by the Escherichia coli Klenow fragment (KF) 3'-5' exonuclease and snake venom phosphodiesterase. To shed light on the origins of nuclease resistance brought about by the AP modification, we determined the crystal structure of an A-form DNA duplex with AP-RNA modifications at 1.6-A resolution. In addition, the crystal structures of complexes between short DNA fragments carrying AP-RNA modifications and wild-type KF were determined at resolutions between 2.2 and 3.0 A and compared with the structure of the complex between oligo(dT) and the D355A/E357A KF mutant. The structural models suggest that interference of the positively charged 2'-O-substituent with the metal ion binding site B of the exonuclease allows AP-RNA to effectively slow down degradation.

 

== References ==

[[Category: Bacillus coli migula 1895]]

[[Category: DNA-directed DNA polymerase]]

[[Category: Cook, P D]]

[[Category: Egli, M]]

[[Category: Manoharan, M]]

[[Category: Minasov, G]]

[[Category: Simons, A M]]

[[Category: Teplova, M]]

[[Category: Tereshko, V]]

[[Category: Wallace, S T]]

[[Category: Transferase/dna]]