2hl2: Difference between revisions
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New page: left|200px<br /><applet load="2hl2" size="450" color="white" frame="true" align="right" spinBox="true" caption="2hl2, resolution 2.60Å" /> '''Crystal structure of... |
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[[Image:2hl2.gif|left|200px]]<br /><applet load="2hl2" size=" | [[Image:2hl2.gif|left|200px]]<br /><applet load="2hl2" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2hl2, resolution 2.60Å" /> | caption="2hl2, resolution 2.60Å" /> | ||
'''Crystal structure of the editing domain of threonyl-tRNA synthetase from Pyrococcus abyssi in complex with an analog of seryladenylate'''<br /> | '''Crystal structure of the editing domain of threonyl-tRNA synthetase from Pyrococcus abyssi in complex with an analog of seryladenylate'''<br /> | ||
==Overview== | ==Overview== | ||
To ensure a high fidelity during translation, threonyl-tRNA synthetases | To ensure a high fidelity during translation, threonyl-tRNA synthetases (ThrRSs) harbor an editing domain that removes noncognate L-serine attached to tRNAThr. Most archaeal ThrRSs possess a unique editing domain structurally similar to D-aminoacyl-tRNA deacylases (DTDs) found in eubacteria and eukaryotes that specifically removes D-amino acids attached to tRNA. Here, we provide mechanistic insights into the removal of noncognate L-serine from tRNAThr by a DTD-like editing module from Pyrococcus abyssi ThrRS (Pab-NTD). High-resolution crystal structures of Pab-NTD with pre- and post-transfer substrate analogs and with L-serine show mutually nonoverlapping binding sites for the seryl moiety. Although the pre-transfer editing is excluded, the analysis reveals the importance of main chain atoms in proper positioning of the post-transfer substrate for its hydrolysis. A single residue has been shown to play a pivotal role in the inversion of enantioselectivity both in Pab-NTD and DTD. The study identifies an enantioselectivity checkpoint that filters opposite chiral molecules and thus provides a fascinating example of how nature has subtly engineered this domain for the selection of chiral molecules during translation. | ||
==About this Structure== | ==About this Structure== | ||
2HL2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_abyssi Pyrococcus abyssi] with SSA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Threonine--tRNA_ligase Threonine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.3 6.1.1.3] Full crystallographic information is available from [http:// | 2HL2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_abyssi Pyrococcus abyssi] with <scene name='pdbligand=SSA:'>SSA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Threonine--tRNA_ligase Threonine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.3 6.1.1.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HL2 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Threonine--tRNA ligase]] | [[Category: Threonine--tRNA ligase]] | ||
[[Category: Hussain, T.]] | [[Category: Hussain, T.]] | ||
[[Category: Kruparani, S | [[Category: Kruparani, S P.]] | ||
[[Category: Pal, B.]] | [[Category: Pal, B.]] | ||
[[Category: Sankaranarayanan, R.]] | [[Category: Sankaranarayanan, R.]] | ||
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[[Category: translation]] | [[Category: translation]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:42:57 2008'' | ||
