View source for 3pky


==Polymerase Domain from Mycobacterium tuberculosis Ligase D in complex with DNA, UTP and Manganese.==
<StructureSection load='3pky' size='340' side='right'caption='[[3pky]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3pky]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PKY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3PKY FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=UTP:URIDINE+5-TRIPHOSPHATE'>UTP</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3pky FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3pky OCA], [https://pdbe.org/3pky PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3pky RCSB], [https://www.ebi.ac.uk/pdbsum/3pky PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3pky ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LIGD_MYCTU LIGD_MYCTU] With Ku forms a non-homologous end joining (NHEJ) repair enzyme which repairs DNA double-strand breaks (DSB) with reduced fidelity. Recognizes, processes and reseals DSBs, including repairs on incompatible DSB which require 3'-resection, gap filling and ligation. Anneals the 3' overhanging strands from opposing breaks to form a gapped intermediate, which then can be extended in trans by using the termini as primers for extension of the annealed break. Binds to the recessed 5'-phosphate moiety of the downstream DNA strand forming a stable synaptic complex even when the 3'-protruding ends of the template DNA strands are not complementary. Has numerous activities; gap filling copies the template strand, and prefers a 5'-phosphate in the gap and rNTPS (PubMed:17174332, PubMed:17947582), DNA-directed DNA or RNA polymerase on 5'-overhangs, terminal transferase (extending ssDNA or blunt dsDNA in a non-templated fashion, preferentially with rNTPs), DNA-dependent RNA primase (synthesizes short RNAs on unprimed closed ssDNA) and 3'- to 5'-exonuclease on ssDNA (PubMed:15499016). Isolated Pol domain (and presumably the holoenzyme) is able to form complexes between 2 noncompatible protruding 3'-ends DNA ends via microhomologous DNA strands, in a end-bridging function to which it adds a templated nucleotide (PubMed:17947582). Minimal primer length is 2 nucleotides (PubMed:21255731).<ref>PMID:15499016</ref> <ref>PMID:17174332</ref> <ref>PMID:17947582</ref> <ref>PMID:21255731</ref>   The preference of the polymerase domain for rNTPs over dNTPs may be advantageous in dormant cells, where the dNTP pool is limiting.  In conjunction with endogenous or Mycobacterium phage Omega Ku (AC Q853W0) can reconstitute NHEJ in Saccharomyces cerevisiae.

==See Also==
*[[DNA ligase 3D structures|DNA ligase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis]]
[[Category: Brissett NC]]
[[Category: Doherty AJ]]
[[Category: Fox GC]]
[[Category: Pitcher RS]]