3nbf: Difference between revisions
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[[ | ==Q28E mutant of hera helicase N-terminal domain bound to 8-oxo-ADP== | ||
<StructureSection load='3nbf' size='340' side='right' caption='[[3nbf]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3nbf]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3NBF OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3NBF FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=8OD:[(2R,3S,4R,5R)-5-(6-AZANYL-8-OXO-7H-PURIN-9-YL)-3,4-DIHYDROXY-OXOLAN-2-YL]METHYL+PHOSPHONO+HYDROGEN+PHOSPHATE'>8OD</scene>, <scene name='pdbligand=8OP:[(2R,3S,4R,5R)-5-(6-AZANYL-8-OXO-7H-PURIN-9-YL)-3,4-DIHYDROXY-OXOLAN-2-YL]METHYL+DIHYDROGEN+PHOSPHATE'>8OP</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3mwj|3mwj]], [[3mwk|3mwk]], [[3mwl|3mwl]]</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=3nbf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3nbf OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3nbf RCSB], [http://www.ebi.ac.uk/pdbsum/3nbf PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Abstract DEAD-box proteins disrupt or remodel RNA and protein/RNA complexes at the expense of ATP. The catalytic core is composed of two flexibly connected RecA-like domains. The N-terminal domain contains most of the motifs involved in nucleotide binding and serves as a minimalistic model for helicase/nucleotide interactions. A single conserved glutamine in the so-called Q-motif has been suggested as a conformational sensor for the nucleotide state. To reprogram the Thermus thermophilus RNA helicase Hera for use of oxo-ATP instead of ATP and to investigate the sensor function of the Q-motif, we analyzed helicase activity of Hera Q28E. Crystal structures of the Hera N-terminal domain Q28E mutant (TthDEAD_Q28E) in apo- and ligand-bound forms show that Q28E does change specificity from adenine to 8-oxoadenine. However, significant structural changes accompany the Q28E mutation, which prevent the P-loop from adopting its catalytically active conformation and explain the lack of helicase activity of Hera_Q28E with either ATP or 8-oxo-ATP as energy sources. 8-Oxo-adenosine, 8-oxo-AMP, and 8-oxo-ADP weakly bind to TthDEAD_Q28E but in non-canonical modes. These results indicate that the Q-motif not only senses the nucleotide state of the helicase but could also stabilize a catalytically competent conformation of the P-loop and other helicase signature motifs. | |||
Changing nucleotide specificity of the DEAD-box helicase Hera abrogates communication between the Q-motif and the P-loop.,Strohmeier J, Hertel I, Diederichsen U, Rudolph MG, Klostermeier D Biol Chem. 2011 Apr;392(4):357-69. PMID:21391900<ref>PMID:21391900</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[ATPase|ATPase]] | *[[ATPase|ATPase]] | ||
*[[Helicase|Helicase]] | *[[Helicase|Helicase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Thermus thermophilus]] | [[Category: Thermus thermophilus]] | ||
[[Category: Klostermeier, D | [[Category: Klostermeier, D]] | ||
[[Category: Rudolph, M G | [[Category: Rudolph, M G]] | ||
[[Category: Atp hydrolysis]] | [[Category: Atp hydrolysis]] | ||
[[Category: Base specificity]] | [[Category: Base specificity]] | ||