1vq7
From Proteopedia
(New page: 200px<br /><applet load="1vq7" size="450" color="white" frame="true" align="right" spinBox="true" caption="1vq7, resolution 2.5Å" /> '''The structure of the ...) |
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| - | [[Image:1vq7.gif|left|200px]]<br /><applet load="1vq7" size=" | + | [[Image:1vq7.gif|left|200px]]<br /><applet load="1vq7" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1vq7, resolution 2.5Å" /> | caption="1vq7, resolution 2.5Å" /> | ||
'''The structure of the transition state analogue "DCA" bound to the large ribosomal subunit of haloarcula marismortui'''<br /> | '''The structure of the transition state analogue "DCA" 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== | ||
| - | 1VQ7 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:// | + | 1VQ7 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=1VQ7 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 15:37:29 2008'' |
Revision as of 13:37, 21 February 2008
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The structure of the transition state analogue "DCA" bound to the large ribosomal subunit of haloarcula marismortui
Overview
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
1VQ7 is a Protein complex structure of sequences from Haloarcula marismortui with , , , and as ligands. Full crystallographic information is available from OCA.
Reference
An induced-fit mechanism to promote peptide bond formation and exclude hydrolysis of peptidyl-tRNA., Schmeing TM, Huang KS, Strobel SA, Steitz TA, Nature. 2005 Nov 24;438(7067):520-4. PMID:16306996
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