1tfw: Difference between revisions
New page: left|200px<br /><applet load="1tfw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tfw, resolution 2.20Å" /> '''How CCA is added to ... |
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[[Image:1tfw.gif|left|200px]]<br /><applet load="1tfw" size=" | [[Image:1tfw.gif|left|200px]]<br /><applet load="1tfw" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1tfw, resolution 2.20Å" /> | caption="1tfw, resolution 2.20Å" /> | ||
'''How CCA is added to the 3' end of immature tRNA without the use of an oligonucleotide template'''<br /> | '''How CCA is added to the 3' end of immature tRNA without the use of an oligonucleotide template'''<br /> | ||
==Overview== | ==Overview== | ||
Transfer RNA nucleotidyltransferases (CCA-adding enzymes) are responsible | Transfer RNA nucleotidyltransferases (CCA-adding enzymes) are responsible for the maturation or repair of the functional 3' end of tRNAs by means of the addition of the essential nucleotides CCA. However, it is unclear how tRNA nucleotidyltransferases polymerize CCA onto the 3' terminus of immature tRNAs without using a nucleic acid template. Here we describe the crystal structure of the Archaeoglobus fulgidus tRNA nucleotidyltransferase in complex with tRNA. We also present ternary complexes of this enzyme with both RNA duplex mimics of the tRNA acceptor stem that terminate with the nucleotides C74 or C75, as well as the appropriate incoming nucleoside 5'-triphosphates. A single nucleotide-binding pocket exists whose specificity for both CTP and ATP is determined by the protein side chain of Arg 224 and backbone phosphates of the tRNA, which are non-complementary to and thus exclude UTP and GTP. Discrimination between CTP or ATP at a given addition step and at termination arises from changes in the size and shape of the nucleotide binding site that is progressively altered by the elongating 3' end of the tRNA. | ||
==About this Structure== | ==About this Structure== | ||
1TFW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus Archaeoglobus fulgidus] with MG and ATP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/tRNA_adenylyltransferase tRNA adenylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.25 2.7.7.25] Full crystallographic information is available from [http:// | 1TFW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus Archaeoglobus fulgidus] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=ATP:'>ATP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/tRNA_adenylyltransferase tRNA adenylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.25 2.7.7.25] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TFW OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: tRNA adenylyltransferase]] | [[Category: tRNA adenylyltransferase]] | ||
[[Category: Steitz, T | [[Category: Steitz, T A.]] | ||
[[Category: Xiong, Y.]] | [[Category: Xiong, Y.]] | ||
[[Category: ATP]] | [[Category: ATP]] | ||
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[[Category: cca-adding complex]] | [[Category: cca-adding complex]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:13:05 2008'' | ||
Revision as of 16:13, 21 February 2008
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How CCA is added to the 3' end of immature tRNA without the use of an oligonucleotide template
OverviewOverview
Transfer RNA nucleotidyltransferases (CCA-adding enzymes) are responsible for the maturation or repair of the functional 3' end of tRNAs by means of the addition of the essential nucleotides CCA. However, it is unclear how tRNA nucleotidyltransferases polymerize CCA onto the 3' terminus of immature tRNAs without using a nucleic acid template. Here we describe the crystal structure of the Archaeoglobus fulgidus tRNA nucleotidyltransferase in complex with tRNA. We also present ternary complexes of this enzyme with both RNA duplex mimics of the tRNA acceptor stem that terminate with the nucleotides C74 or C75, as well as the appropriate incoming nucleoside 5'-triphosphates. A single nucleotide-binding pocket exists whose specificity for both CTP and ATP is determined by the protein side chain of Arg 224 and backbone phosphates of the tRNA, which are non-complementary to and thus exclude UTP and GTP. Discrimination between CTP or ATP at a given addition step and at termination arises from changes in the size and shape of the nucleotide binding site that is progressively altered by the elongating 3' end of the tRNA.
About this StructureAbout this Structure
1TFW is a Single protein structure of sequence from Archaeoglobus fulgidus with and as ligands. Active as tRNA adenylyltransferase, with EC number 2.7.7.25 Full crystallographic information is available from OCA.
ReferenceReference
Mechanism of transfer RNA maturation by CCA-adding enzyme without using an oligonucleotide template., Xiong Y, Steitz TA, Nature. 2004 Aug 5;430(7000):640-5. PMID:15295590
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