1tfw: Difference between revisions

Revision as of 09:54, 3 May 2008

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. 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 Page seeded by OCA on Sat May 3 09:54:20 2008

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OCA

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 [[Image:1tfw.gif|left|200px]]
- {{Structure
+<!--
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+The line below this paragraph, containing "STRUCTURE_1tfw", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=A:ADENOSINE-5&#39;-MONOPHOSPHATE'>A</scene>, <scene name='pdbligand=ATP:ADENOSINE-5&#39;-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=C:CYTIDINE-5&#39;-MONOPHOSPHATE'>C</scene>, <scene name='pdbligand=G:GUANOSINE-5&#39;-MONOPHOSPHATE'>G</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=U:URIDINE-5&#39;-MONOPHOSPHATE'>U</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[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] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE= CCA, AF2156 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=2234 Archaeoglobus fulgidus])
+-->
-|DOMAIN=
+{{STRUCTURE_1tfw|  PDB=1tfw  |  SCENE=  }}
-|RELATEDENTRY=[[1sz1|1SZ1]], [[1tfy|1TFY]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tfw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tfw OCA], [http://www.ebi.ac.uk/pdbsum/1tfw PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1tfw RCSB]</span>
-}}
 '''How CCA is added to the 3' end of immature tRNA without the use of an oligonucleotide template'''
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 [[Category: Archaeoglobus fulgidus]]
 [[Category: Single protein]]
-[[Category: tRNA adenylyltransferase]]
+[[Category: TRNA adenylyltransferase]]
 [[Category: Steitz, T A.]]
 [[Category: Xiong, Y.]]
-[[Category: atp]]
+[[Category: Atp]]
-[[Category: cca-adding complex]]
+[[Category: Cca-adding complex]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 09:54:20 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:55:30 2008''