2cyc

<table><tr><td colspan='2'>[[2cyc]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CYC OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=2CYC FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=TYR:TYROSINE'>TYR</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Tyrosine--tRNA_ligase Tyrosine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.1 6.1.1.1] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=2cyc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2cyc OCA], [http://pdbe.org/2cyc PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2cyc RCSB], [http://www.ebi.ac.uk/pdbsum/2cyc PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2cyc ProSAT], [http://www.topsan.org/Proteins/RSGI/2cyc TOPSAN]</span></td></tr>

[[http://www.uniprot.org/uniprot/SYY_PYRHO SYY_PYRHO]] Catalyzes the attachment of tyrosine to tRNA(Tyr) in a two-step reaction: tyrosine is first activated by ATP to form Tyr-AMP and then transferred to the acceptor end of tRNA(Tyr).[HAMAP-Rule:MF_02009]

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== Publication Abstract from PubMed ==

Tyrosyl-tRNA synthetase (TyrRS) catalyzes the tyrosylation of tRNA(Tyr) in a two-step reaction. TyrRS has the "HIGH" and "KMSKS" motifs, which play essential roles in the formation of the tyrosyl-adenylate from tyrosine and ATP. Here, we determined the crystal structures of Archaeoglobus fulgidus and Pyrococcus horikoshii TyrRSs in the l-tyrosine-bound form at 1.8A and 2.2A resolutions, respectively, and that of Aeropyrum pernix TyrRS in the substrate-free form at 2.2 A. The conformation of the KMSKS motif differs among the three TyrRSs. In the A.pernix TyrRS, the KMSKS loop conformation corresponds to the ATP-bound "closed" form. In contrast, the KMSKS loop of the P.horikoshii TyrRS forms a novel 3(10) helix, which appears to correspond to the "semi-closed" form. This conformation enlarges the entrance to the tyrosine-binding pocket, which facilitates the pyrophosphate ion release after the tyrosyl-adenylate formation, and probably is involved in the initial tRNA binding. The KMSSS loop of the A.fulgidus TyrRS is somewhat farther from the active site and is stabilized by hydrogen bonds. Based on the three structures, possible structural changes of the KMSKS motif during the tyrosine activation reaction are discussed. We suggest that the insertion sequence just before the KMSKS motif, which exists in some archaeal species, enhances the binding affinity of the TyrRS for its cognate tRNA. In addition, a non-proline cis peptide bond, which is involved in the tRNA binding, is conserved among the archaeal TyrRSs.

Crystal structures of tyrosyl-tRNA synthetases from Archaea.,Kuratani M, Sakai H, Takahashi M, Yanagisawa T, Kobayashi T, Murayama K, Chen L, Liu ZJ, Wang BC, Kuroishi C, Kuramitsu S, Terada T, Bessho Y, Shirouzu M, Sekine S, Yokoyama S J Mol Biol. 2006 Jan 20;355(3):395-408. Epub 2005 Nov 14. PMID:16325203<ref>PMID:16325203</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 2cyc" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Pyrococcus horikoshii]]

[[Category: Tyrosine--tRNA ligase]]

[[Category: Kobayashi, T]]

[[Category: Kuratani, M]]

[[Category: Structural genomic]]

[[Category: Sakai, H]]

[[Category: Sakamoto, K]]

[[Category: Sekine, S]]

[[Category: Shirouzu, M]]

[[Category: Takahashi, M]]

[[Category: Terada, T]]

[[Category: Yanagisawa, T]]

[[Category: Yokoyama, S]]

[[Category: Tyrr]]