3w1k: Difference between revisions
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==Crystal structure of the selenocysteine synthase SelA and tRNASec complex== | |||
<StructureSection load='3w1k' size='340' side='right'caption='[[3w1k]], [[Resolution|resolution]] 7.50Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3w1k]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Aquifex_aeolicus_VF5 Aquifex aeolicus VF5] and [https://en.wikipedia.org/wiki/Caldanaerobacter_subterraneus_subsp._tengcongensis_MB4 Caldanaerobacter subterraneus subsp. tengcongensis MB4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3W1K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3W1K 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]] 7.5Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LLP:(2S)-2-AMINO-6-[[3-HYDROXY-2-METHYL-5-(PHOSPHONOOXYMETHYL)PYRIDIN-4-YL]METHYLIDENEAMINO]HEXANOIC+ACID'>LLP</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=3w1k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3w1k OCA], [https://pdbe.org/3w1k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3w1k RCSB], [https://www.ebi.ac.uk/pdbsum/3w1k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3w1k ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/SELA_AQUAE SELA_AQUAE] Converts seryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec) required for selenoprotein biosynthesis (By similarity). | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The 21st amino acid, selenocysteine (Sec), is synthesized on its cognate transfer RNA (tRNA(Sec)). In bacteria, SelA synthesizes Sec from Ser-tRNA(Sec), whereas in archaea and eukaryotes SepSecS forms Sec from phosphoserine (Sep) acylated to tRNA(Sec). We determined the crystal structures of Aquifex aeolicus SelA complexes, which revealed a ring-shaped homodecamer that binds 10 tRNA(Sec) molecules, each interacting with four SelA subunits. The SelA N-terminal domain binds the tRNA(Sec)-specific D-arm structure, thereby discriminating Ser-tRNA(Sec) from Ser-tRNA(Ser). A large cleft is created between two subunits and accommodates the 3'-terminal region of Ser-tRNA(Sec). The SelA structures together with in vivo and in vitro enzyme assays show decamerization to be essential for SelA function. SelA catalyzes pyridoxal 5'-phosphate-dependent Sec formation involving Arg residues nonhomologous to those in SepSecS. Different protein architecture and substrate coordination of the bacterial enzyme provide structural evidence for independent evolution of the two Sec synthesis systems present in nature. | |||
Decameric SelA*tRNA(Sec) ring structure reveals mechanism of bacterial selenocysteine formation.,Itoh Y, Brocker MJ, Sekine S, Hammond G, Suetsugu S, Soll D, Yokoyama S Science. 2013 Apr 5;340(6128):75-8. doi: 10.1126/science.1229521. PMID:23559248<ref>PMID:23559248</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3w1k" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Selenocysteine synthase|Selenocysteine synthase]] | |||
*[[Transfer RNA (tRNA)|Transfer RNA (tRNA)]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Aquifex aeolicus VF5]] | |||
[[Category: Caldanaerobacter subterraneus subsp. tengcongensis MB4]] | |||
[[Category: Large Structures]] | |||
[[Category: Itoh Y]] | |||
[[Category: Sekine S]] | |||
[[Category: Yokoyama S]] | |||
Latest revision as of 15:45, 8 November 2023
Crystal structure of the selenocysteine synthase SelA and tRNASec complexCrystal structure of the selenocysteine synthase SelA and tRNASec complex
Structural highlights
FunctionSELA_AQUAE Converts seryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec) required for selenoprotein biosynthesis (By similarity). Publication Abstract from PubMedThe 21st amino acid, selenocysteine (Sec), is synthesized on its cognate transfer RNA (tRNA(Sec)). In bacteria, SelA synthesizes Sec from Ser-tRNA(Sec), whereas in archaea and eukaryotes SepSecS forms Sec from phosphoserine (Sep) acylated to tRNA(Sec). We determined the crystal structures of Aquifex aeolicus SelA complexes, which revealed a ring-shaped homodecamer that binds 10 tRNA(Sec) molecules, each interacting with four SelA subunits. The SelA N-terminal domain binds the tRNA(Sec)-specific D-arm structure, thereby discriminating Ser-tRNA(Sec) from Ser-tRNA(Ser). A large cleft is created between two subunits and accommodates the 3'-terminal region of Ser-tRNA(Sec). The SelA structures together with in vivo and in vitro enzyme assays show decamerization to be essential for SelA function. SelA catalyzes pyridoxal 5'-phosphate-dependent Sec formation involving Arg residues nonhomologous to those in SepSecS. Different protein architecture and substrate coordination of the bacterial enzyme provide structural evidence for independent evolution of the two Sec synthesis systems present in nature. Decameric SelA*tRNA(Sec) ring structure reveals mechanism of bacterial selenocysteine formation.,Itoh Y, Brocker MJ, Sekine S, Hammond G, Suetsugu S, Soll D, Yokoyama S Science. 2013 Apr 5;340(6128):75-8. doi: 10.1126/science.1229521. PMID:23559248[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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