1it8: Difference between revisions

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Crystal structure of archaeosine tRNA-guanine transglycosylase from Pyrococcus horikoshii complexed with archaeosine precursor, preQ0

OverviewOverview

Archaeosine tRNA-guanine transglycosylase (ArcTGT) catalyzes the exchange of guanine at position 15 in the D-loop of archaeal tRNAs with a free 7-cyano-7-deazaguanine (preQ(0)) base, as the first step in the biosynthesis of an archaea-specific modified base, archaeosine (7-formamidino-7-deazaguanosine). We determined the crystal structures of ArcTGT from Pyrococcus horikoshii at 2.2 A resolution and its complexes with guanine and preQ(0), at 2.3 and 2.5 A resolutions, respectively. The N-terminal catalytic domain folds into an (alpha/beta)(8) barrel with a characteristic zinc-binding site, showing structural similarity with that of the bacterial queuosine TGT (QueTGT), which is involved in queuosine (7-[[(4,5-cis-dihydroxy-2-cyclopenten-1-yl)-amino]methyl]-7-deazaguanosine ) biosynthesis and targets the tRNA anticodon. ArcTGT forms a dimer, involving the zinc-binding site and the ArcTGT-specific C-terminal domain. The C-terminal domains have novel folds, including an OB fold-like "PUA domain", whose sequence is widely conserved in eukaryotic and archaeal RNA modification enzymes. Therefore, the C-terminal domains may be involved in tRNA recognition. In the free-form structure of ArcTGT, an alpha-helix located at the rim of the (alpha/beta)(8) barrel structure is completely disordered, while it is ordered in the guanine-bound and preQ(0)-bound forms. Structural comparison of the ArcTGT.preQ(0), ArcTGT.guanine, and QueTGT.preQ(1) complexes provides novel insights into the substrate recognition mechanisms of ArcTGT.

About this StructureAbout this Structure

1IT8 is a Single protein structure of sequence from Pyrococcus horikoshii with , and as ligands. Active as Queuine tRNA-ribosyltransferase, with EC number 2.4.2.29 Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of archaeosine tRNA-guanine transglycosylase., Ishitani R, Nureki O, Fukai S, Kijimoto T, Nameki N, Watanabe M, Kondo H, Sekine M, Okada N, Nishimura S, Yokoyama S, J Mol Biol. 2002 May 3;318(3):665-77. PMID:12054814

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OCA

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-[[Image:1it8.jpg|left|200px]]<br /><applet load="1it8" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1it8.jpg|left|200px]]<br /><applet load="1it8" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1it8, resolution 2.50&Aring;" />
 '''Crystal structure of archaeosine tRNA-guanine transglycosylase from Pyrococcus horikoshii complexed with archaeosine precursor, preQ0'''<br />
 ==Overview==
-Archaeosine tRNA-guanine transglycosylase (ArcTGT) catalyzes the exchange, of guanine at position 15 in the D-loop of archaeal tRNAs with a free, 7-cyano-7-deazaguanine (preQ(0)) base, as the first step in the, biosynthesis of an archaea-specific modified base, archaeosine, (7-formamidino-7-deazaguanosine). We determined the crystal structures of, ArcTGT from Pyrococcus horikoshii at 2.2 A resolution and its complexes, with guanine and preQ(0), at 2.3 and 2.5 A resolutions, respectively. The, N-terminal catalytic domain folds into an (alpha/beta)(8) barrel with a, characteristic zinc-binding site, showing structural similarity with that, of the bacterial queuosine TGT (QueTGT), which is involved in queuosine, (7-[[(4,5-cis-dihydroxy-2-cyclopenten-1-yl)-amino]methyl]-7-deazaguanosine, ) biosynthesis and targets the tRNA anticodon. ArcTGT forms a dimer, involving the zinc-binding site and the ArcTGT-specific C-terminal domain., The C-terminal domains have novel folds, including an OB fold-like "PUA, domain", whose sequence is widely conserved in eukaryotic and archaeal RNA, modification enzymes. Therefore, the C-terminal domains may be involved in, tRNA recognition. In the free-form structure of ArcTGT, an alpha-helix, located at the rim of the (alpha/beta)(8) barrel structure is completely, disordered, while it is ordered in the guanine-bound and preQ(0)-bound, forms. Structural comparison of the ArcTGT.preQ(0), ArcTGT.guanine, and, QueTGT.preQ(1) complexes provides novel insights into the substrate, recognition mechanisms of ArcTGT.
+Archaeosine tRNA-guanine transglycosylase (ArcTGT) catalyzes the exchange of guanine at position 15 in the D-loop of archaeal tRNAs with a free 7-cyano-7-deazaguanine (preQ(0)) base, as the first step in the biosynthesis of an archaea-specific modified base, archaeosine (7-formamidino-7-deazaguanosine). We determined the crystal structures of ArcTGT from Pyrococcus horikoshii at 2.2 A resolution and its complexes with guanine and preQ(0), at 2.3 and 2.5 A resolutions, respectively. The N-terminal catalytic domain folds into an (alpha/beta)(8) barrel with a characteristic zinc-binding site, showing structural similarity with that of the bacterial queuosine TGT (QueTGT), which is involved in queuosine (7-[[(4,5-cis-dihydroxy-2-cyclopenten-1-yl)-amino]methyl]-7-deazaguanosine ) biosynthesis and targets the tRNA anticodon. ArcTGT forms a dimer, involving the zinc-binding site and the ArcTGT-specific C-terminal domain. The C-terminal domains have novel folds, including an OB fold-like "PUA domain", whose sequence is widely conserved in eukaryotic and archaeal RNA modification enzymes. Therefore, the C-terminal domains may be involved in tRNA recognition. In the free-form structure of ArcTGT, an alpha-helix located at the rim of the (alpha/beta)(8) barrel structure is completely disordered, while it is ordered in the guanine-bound and preQ(0)-bound forms. Structural comparison of the ArcTGT.preQ(0), ArcTGT.guanine, and QueTGT.preQ(1) complexes provides novel insights into the substrate recognition mechanisms of ArcTGT.
 ==About this Structure==
-IT8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii] with ZN, MG and PQ0 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Queuine_tRNA-ribosyltransferase Queuine tRNA-ribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.29 2.4.2.29] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1IT8 OCA].
+IT8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=PQ0:'>PQ0</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Queuine_tRNA-ribosyltransferase Queuine tRNA-ribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.29 2.4.2.29] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IT8 OCA].
 ==Reference==
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 [[Category: Nureki, O.]]
 [[Category: Okada, N.]]
-[[Category: RSGI, RIKEN.Structural.Genomics/Proteomics.Initiative.]]
+[[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]]
 [[Category: Sekine, M.]]
 [[Category: Watanabe, M.]]
@@ Line 34: / Line 34: @@
 [[Category: structural genomics]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 17:39:10 2007''
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