View source for 6ppr


==Cryo-EM structure of AdnA(D934A)-AdnB(D1014A) in complex with AMPPNP and DNA==
<SX load='6ppr' size='340' side='right' viewer='molstar' caption='[[6ppr]], [[Resolution|resolution]] 3.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6ppr]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycolicibacterium_smegmatis Mycolicibacterium smegmatis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6PPR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6PPR FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</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=6ppr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ppr OCA], [https://pdbe.org/6ppr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ppr RCSB], [https://www.ebi.ac.uk/pdbsum/6ppr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ppr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/I7FZ56_MYCS2 I7FZ56_MYCS2] 
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== Publication Abstract from PubMed ==
Mycobacterial AdnAB is a heterodimeric helicase-nuclease that initiates homologous recombination by resecting DNA double-strand breaks (DSBs). The AdnA and AdnB subunits are each composed of an N-terminal motor domain and a C-terminal nuclease domain. Here we report cryoelectron microscopy (cryo-EM) structures of AdnAB in three functional states: in the absence of DNA and in complex with forked duplex DNAs before and after cleavage of the 5' single-strand DNA (ssDNA) tail by the AdnA nuclease. The structures reveal the path of the 5' ssDNA through the AdnA nuclease domain and the mechanism of 5' strand cleavage; the path of the 3' tracking strand through the AdnB motor and the DNA contacts that couple ATP hydrolysis to mechanical work; the position of the AdnA iron-sulfur cluster subdomain at the Y junction and its likely role in maintaining the split trajectories of the unwound 5' and 3' strands. Single-molecule DNA curtain analysis of DSB resection reveals that AdnAB is highly processive but prone to spontaneous pausing at random sites on duplex DNA. A striking property of AdnAB is that the velocity of DSB resection slows after the enzyme experiences a spontaneous pause. Our results highlight shared as well as distinctive properties of AdnAB vis-a-vis the RecBCD and AddAB clades of bacterial DSB-resecting motor nucleases.

Structures and single-molecule analysis of bacterial motor nuclease AdnAB illuminate the mechanism of DNA double-strand break resection.,Jia N, Unciuleac MC, Xue C, Greene EC, Patel DJ, Shuman S Proc Natl Acad Sci U S A. 2019 Nov 18. pii: 1913546116. doi:, 10.1073/pnas.1913546116. PMID:31740608<ref>PMID:31740608</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6ppr" style="background-color:#fffaf0;"></div>

==See Also==
*[[Helicase 3D structures|Helicase 3D structures]]
== References ==
<references/>
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[[Category: Large Structures]]
[[Category: Mycolicibacterium smegmatis]]
[[Category: Jia N]]
[[Category: Patel DJ]]
[[Category: Shuman S]]
[[Category: Unciuleac M]]