View source for 4acb


==CRYSTAL STRUCTURE OF TRANSLATION ELONGATION FACTOR SELB FROM METHANOCOCCUS MARIPALUDIS IN COMPLEX WITH THE GTP ANALOGUE GPPNHP==
<StructureSection load='4acb' size='340' side='right'caption='[[4acb]], [[Resolution|resolution]] 3.34&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4acb]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Methanococcus_maripaludis Methanococcus maripaludis]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1wb3 1wb3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ACB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ACB 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]] 3.34&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=5GP:GUANOSINE-5-MONOPHOSPHATE'>5GP</scene>, <scene name='pdbligand=CMH:S-(METHYLMERCURY)-L-CYSTEINE'>CMH</scene>, <scene name='pdbligand=DXC:(3ALPHA,5BETA,12ALPHA)-3,12-DIHYDROXYCHOLAN-24-OIC+ACID'>DXC</scene>, <scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=GNP:PHOSPHOAMINOPHOSPHONIC+ACID-GUANYLATE+ESTER'>GNP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4acb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4acb OCA], [https://pdbe.org/4acb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4acb RCSB], [https://www.ebi.ac.uk/pdbsum/4acb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4acb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q8J307_METMI Q8J307_METMI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
In all three kingdoms of life, SelB is a specialized translation elongation factor responsible for the cotranslational incorporation of selenocysteine into proteins by recoding of a UGA stop codon in the presence of a downstream mRNA hairpin loop. Here, we present the X-ray structures of SelB from the archaeon Methanococcus maripaludis in the apo-, GDP- and GppNHp-bound form and use mutational analysis to investigate the role of individual amino acids in its aminoacyl-binding pocket. All three SelB structures reveal an EF-Tu:GTP-like domain arrangement. Upon binding of the GTP analogue GppNHp, a conformational change of the Switch 2 region in the GTPase domain leads to the exposure of SelB residues involved in clamping the 5' phosphate of the tRNA. A conserved extended loop in domain III of SelB may be responsible for specific interactions with tRNA(Sec) and act as a ruler for measuring the extra long acceptor arm. Domain IV of SelB adopts a beta barrel fold and is flexibly tethered to domain III. The overall domain arrangement of SelB resembles a 'chalice' observed so far only for initiation factor IF2/eIF5B. In our model of SelB bound to the ribosome, domain IV points towards the 3' mRNA entrance cleft ready to interact with the downstream secondary structure element.

Selenocysteine tRNA-specific elongation factor SelB is a structural chimaera of elongation and initiation factors.,Leibundgut M, Frick C, Thanbichler M, Bock A, Ban N EMBO J. 2005 Jan 12;24(1):11-22. Epub 2004 Dec 23. PMID:15616587<ref>PMID:15616587</ref>

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

==See Also==
*[[Elongation factor 3D structures|Elongation factor 3D structures]]
*[[SelB|SelB]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Methanococcus maripaludis]]
[[Category: Ban N]]
[[Category: Boeck A]]
[[Category: Frick C]]
[[Category: Leibundgut M]]
[[Category: Thanbichler M]]