2dfx: Difference between revisions

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[[Image:2dfx.gif|left|200px]]<br /><applet load="2dfx" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:2dfx.gif|left|200px]]<br /><applet load="2dfx" size="350" color="white" frame="true" align="right" spinBox="true"

caption="2dfx, resolution 1.9Å" />

'''Crystal structure of the carboxy terminal domain of colicin E5 complexed with its inhibitor'''<br />

==Overview==

Colicin E5--a tRNase toxin--specifically cleaves QUN (Q: queuosine), anticodons of the Escherichia coli tRNAs for Tyr, His, Asn and Asp. Here, we report the crystal structure of the C-terminal ribonuclease domain, (CRD) of E5 complexed with a substrate analog, namely, dGpdUp, at a, resolution of 1.9 A. Thisstructure is the first to reveal the substrate, recognition mechanism of sequence-specific ribonucleases. E5-CRD realized, the strict recognition for both the guanine and uracil bases of dGpdUp, forming Watson-Crick-type hydrogen bonds and ring stacking interactions, thus mimicking the codons of mRNAs to bind to tRNA anticodons. The docking, model of E5-CRD with tRNA also suggests its substrate preference for tRNA, over ssRNA. In addition, the structure of E5-CRD/dGpdUp along with the, mutational analysis suggests that Arg33 may play an important role in the, catalytic activity, and Lys25/Lys60 may also be involved without His in, E5-CRD. Finally, the comparison of the structures of E5-CRD/dGpdUp and, E5-CRD/ImmE5 (an inhibitor protein) complexes suggests that the binding, mode of E5-CRD and ImmE5 mimics that of mRNA and tRNA; this may represent, the evolutionary pathway of these proteins from the RNA-RNA interaction, through the RNA-protein interaction of tRNA/E5-CRD.

Colicin E5--a tRNase toxin--specifically cleaves QUN (Q: queuosine) anticodons of the Escherichia coli tRNAs for Tyr, His, Asn and Asp. Here, we report the crystal structure of the C-terminal ribonuclease domain (CRD) of E5 complexed with a substrate analog, namely, dGpdUp, at a resolution of 1.9 A. Thisstructure is the first to reveal the substrate recognition mechanism of sequence-specific ribonucleases. E5-CRD realized the strict recognition for both the guanine and uracil bases of dGpdUp forming Watson-Crick-type hydrogen bonds and ring stacking interactions, thus mimicking the codons of mRNAs to bind to tRNA anticodons. The docking model of E5-CRD with tRNA also suggests its substrate preference for tRNA over ssRNA. In addition, the structure of E5-CRD/dGpdUp along with the mutational analysis suggests that Arg33 may play an important role in the catalytic activity, and Lys25/Lys60 may also be involved without His in E5-CRD. Finally, the comparison of the structures of E5-CRD/dGpdUp and E5-CRD/ImmE5 (an inhibitor protein) complexes suggests that the binding mode of E5-CRD and ImmE5 mimics that of mRNA and tRNA; this may represent the evolutionary pathway of these proteins from the RNA-RNA interaction through the RNA-protein interaction of tRNA/E5-CRD.

==About this Structure==

2DFX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=2DFX OCA].

2DFX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2DFX OCA].

==Reference==

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[[Category: protein-inhibitor protein complex]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Wed Nov~~ 21 09:35:~~41 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:58:22 2008''

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@@ Line 1: / Line 1: @@
-[[Image:2dfx.gif|left|200px]]<br /><applet load="2dfx" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2dfx.gif|left|200px]]<br /><applet load="2dfx" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2dfx, resolution 1.9&Aring;" />
 '''Crystal structure of the carboxy terminal domain of colicin E5 complexed with its inhibitor'''<br />
 ==Overview==
-Colicin E5--a tRNase toxin--specifically cleaves QUN (Q: queuosine), anticodons of the Escherichia coli tRNAs for Tyr, His, Asn and Asp. Here, we report the crystal structure of the C-terminal ribonuclease domain, (CRD) of E5 complexed with a substrate analog, namely, dGpdUp, at a, resolution of 1.9 A. Thisstructure is the first to reveal the substrate, recognition mechanism of sequence-specific ribonucleases. E5-CRD realized, the strict recognition for both the guanine and uracil bases of dGpdUp, forming Watson-Crick-type hydrogen bonds and ring stacking interactions, thus mimicking the codons of mRNAs to bind to tRNA anticodons. The docking, model of E5-CRD with tRNA also suggests its substrate preference for tRNA, over ssRNA. In addition, the structure of E5-CRD/dGpdUp along with the, mutational analysis suggests that Arg33 may play an important role in the, catalytic activity, and Lys25/Lys60 may also be involved without His in, E5-CRD. Finally, the comparison of the structures of E5-CRD/dGpdUp and, E5-CRD/ImmE5 (an inhibitor protein) complexes suggests that the binding, mode of E5-CRD and ImmE5 mimics that of mRNA and tRNA; this may represent, the evolutionary pathway of these proteins from the RNA-RNA interaction, through the RNA-protein interaction of tRNA/E5-CRD.
+Colicin E5--a tRNase toxin--specifically cleaves QUN (Q: queuosine) anticodons of the Escherichia coli tRNAs for Tyr, His, Asn and Asp. Here, we report the crystal structure of the C-terminal ribonuclease domain (CRD) of E5 complexed with a substrate analog, namely, dGpdUp, at a resolution of 1.9 A. Thisstructure is the first to reveal the substrate recognition mechanism of sequence-specific ribonucleases. E5-CRD realized the strict recognition for both the guanine and uracil bases of dGpdUp forming Watson-Crick-type hydrogen bonds and ring stacking interactions, thus mimicking the codons of mRNAs to bind to tRNA anticodons. The docking model of E5-CRD with tRNA also suggests its substrate preference for tRNA over ssRNA. In addition, the structure of E5-CRD/dGpdUp along with the mutational analysis suggests that Arg33 may play an important role in the catalytic activity, and Lys25/Lys60 may also be involved without His in E5-CRD. Finally, the comparison of the structures of E5-CRD/dGpdUp and E5-CRD/ImmE5 (an inhibitor protein) complexes suggests that the binding mode of E5-CRD and ImmE5 mimics that of mRNA and tRNA; this may represent the evolutionary pathway of these proteins from the RNA-RNA interaction through the RNA-protein interaction of tRNA/E5-CRD.
 ==About this Structure==
-DFX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2DFX OCA].
+DFX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2DFX OCA].
 ==Reference==
@@ Line 22: / Line 22: @@
 [[Category: protein-inhibitor protein complex]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 09:35:41 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:58:22 2008''