View source for 4csu


==Cryo-EM structures of the 50S ribosome subunit bound with ObgE==
<SX load='4csu' size='340' side='right' viewer='molstar' caption='[[4csu]], [[Resolution|resolution]] 5.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4csu]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4CSU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4CSU 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]] 5.5&#8491;</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=4csu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4csu OCA], [https://pdbe.org/4csu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4csu RCSB], [https://www.ebi.ac.uk/pdbsum/4csu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4csu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RL34_ECOLI RL34_ECOLI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Obg proteins are a family of P-loop GTPases, conserved from bacteria to human. The Obg protein in Escherichia coli (ObgE) has been implicated in many diverse cellular functions, with proposed molecular roles in two global processes, ribosome assembly and stringent response. Here, using pre-steady state fast kinetics we demonstrate that ObgE is an anti-association factor, which prevents ribosomal subunit association and downstream steps in translation by binding to the 50S subunit. ObgE is a ribosome dependent GTPase; however, upon binding to guanosine tetraphosphate (ppGpp), the global regulator of stringent response, ObgE exhibits an enhanced interaction with the 50S subunit, resulting in increased equilibrium dissociation of the 70S ribosome into subunits. Furthermore, our cryo-electron microscopy (cryo-EM) structure of the 50S.ObgE.GMPPNP complex indicates that the evolutionarily conserved N-terminal domain (NTD) of ObgE is a tRNA structural mimic, with specific interactions with peptidyl-transferase center, displaying a marked resemblance to Class I release factors. These structural data might define ObgE as a specialized translation factor related to stress responses, and provide a framework towards future elucidation of functional interplay between ObgE and ribosome-associated (p)ppGpp regulators. Together with published data, our results suggest that ObgE might act as a checkpoint in final stages of the 50S subunit assembly under normal growth conditions. And more importantly, ObgE, as a (p)ppGpp effector, might also have a regulatory role in the production of the 50S subunit and its participation in translation under certain stressed conditions. Thus, our findings might have uncovered an under-recognized mechanism of translation control by environmental cues.

Structural and Functional Insights into the Mode of Action of a Universally Conserved Obg GTPase.,Feng B, Mandava CS, Guo Q, Wang J, Cao W, Li N, Zhang Y, Zhang Y, Wang Z, Wu J, Sanyal S, Lei J, Gao N PLoS Biol. 2014 May 20;12(5):e1001866. doi: 10.1371/journal.pbio.1001866., eCollection 2014 May. PMID:24844575<ref>PMID:24844575</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4csu" style="background-color:#fffaf0;"></div>

==See Also==
*[[GTP-binding protein 3D structures|GTP-binding protein 3D structures]]
*[[Ribosome 3D structures|Ribosome 3D structures]]
== References ==
<references/>
__TOC__
</SX>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Cao W]]
[[Category: Feng B]]
[[Category: Gao N]]
[[Category: Guo Q]]
[[Category: Lei J]]
[[Category: Li N]]
[[Category: Mandava CS]]
[[Category: Sanyal S]]
[[Category: Wang J]]
[[Category: Wang Z]]
[[Category: Wu J]]
[[Category: Zhang Y]]