1vq6: Difference between revisions
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New page: left|200px<br /><applet load="1vq6" size="450" color="white" frame="true" align="right" spinBox="true" caption="1vq6, resolution 2.7Å" /> '''The structure of c-hp... |
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[[Image:1vq6.gif|left|200px]]<br /><applet load="1vq6" size=" | [[Image:1vq6.gif|left|200px]]<br /><applet load="1vq6" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1vq6, resolution 2.7Å" /> | caption="1vq6, resolution 2.7Å" /> | ||
'''The structure of c-hpmn and CCA-PHE-CAP-BIO bound to the large ribosomal subunit of haloarcula marismortui'''<br /> | '''The structure of c-hpmn and CCA-PHE-CAP-BIO bound to the large ribosomal subunit of haloarcula marismortui'''<br /> | ||
==Overview== | ==Overview== | ||
The large ribosomal subunit catalyses the reaction between the alpha-amino | The large ribosomal subunit catalyses the reaction between the alpha-amino group of the aminoacyl-tRNA bound to the A site and the ester carbon of the peptidyl-tRNA bound to the P site, while preventing the nucleophilic attack of water on the ester, which would lead to unprogrammed deacylation of the peptidyl-tRNA. Here we describe three new structures of the large ribosomal subunit of Haloarcula marismortui (Hma) complexed with peptidyl transferase substrate analogues that reveal an induced-fit mechanism in which substrates and active-site residues reposition to allow the peptidyl transferase reaction. Proper binding of an aminoacyl-tRNA analogue to the A site induces specific movements of 23S rRNA nucleotides 2618-2620 (Escherichia coli numbering 2583-2585) and 2541(2506), thereby reorienting the ester group of the peptidyl-tRNA and making it accessible for attack. In the absence of the appropriate A-site substrate, the peptidyl transferase centre positions the ester link of the peptidyl-tRNA in a conformation that precludes the catalysed nucleophilic attack by water. Protein release factors may also function, in part, by inducing an active-site rearrangement similar to that produced by the A-site aminoacyl-tRNA, allowing the carbonyl group and water to be positioned for hydrolysis. | ||
==About this Structure== | ==About this Structure== | ||
1VQ6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Haloarcula_marismortui Haloarcula marismortui] with MG, K, NA, CD and CL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1VQ6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Haloarcula_marismortui Haloarcula marismortui] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=K:'>K</scene>, <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=CD:'>CD</scene> and <scene name='pdbligand=CL:'>CL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VQ6 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Haloarcula marismortui]] | [[Category: Haloarcula marismortui]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Schmeing, T | [[Category: Schmeing, T M.]] | ||
[[Category: Steitz, T | [[Category: Steitz, T A.]] | ||
[[Category: CD]] | [[Category: CD]] | ||
[[Category: CL]] | [[Category: CL]] | ||
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[[Category: rna-rna complex]] | [[Category: rna-rna complex]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:37:34 2008'' | ||
