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1it7
From Proteopedia
(New page: 200px<br /><applet load="1it7" size="450" color="white" frame="true" align="right" spinBox="true" caption="1it7, resolution 2.30Å" /> '''Crystal structure of...) |
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| - | [[Image:1it7.gif|left|200px]]<br /><applet load="1it7" size=" | + | [[Image:1it7.gif|left|200px]]<br /><applet load="1it7" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1it7, resolution 2.30Å" /> | caption="1it7, resolution 2.30Å" /> | ||
'''Crystal structure of archaeosine tRNA-guanine transglycosylase complexed with guanine'''<br /> | '''Crystal structure of archaeosine tRNA-guanine transglycosylase complexed with guanine'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Archaeosine tRNA-guanine transglycosylase (ArcTGT) catalyzes the exchange | + | 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== | ==About this Structure== | ||
| - | 1IT7 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 GUN 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:// | + | 1IT7 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=GUN:'>GUN</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=1IT7 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Nureki, O.]] | [[Category: Nureki, O.]] | ||
[[Category: Okada, N.]] | [[Category: Okada, N.]] | ||
| - | [[Category: RSGI, RIKEN | + | [[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]] |
[[Category: Sekine, M.]] | [[Category: Sekine, M.]] | ||
[[Category: Watanabe, M.]] | [[Category: Watanabe, M.]] | ||
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[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:15:25 2008'' |
Revision as of 11:15, 21 February 2008
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Crystal structure of archaeosine tRNA-guanine transglycosylase complexed with guanine
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.
About this Structure
1IT7 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.
Reference
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
Page seeded by OCA on Thu Feb 21 13:15:25 2008
Categories: Pyrococcus horikoshii | Queuine tRNA-ribosyltransferase | Single protein | Fukai, S. | Ishitani, R. | Kijimoto, T. | Kondo, H. | Nameki, N. | Nishimura, S. | Nureki, O. | Okada, N. | RSGI, RIKEN Structural Genomics/Proteomics Initiative. | Sekine, M. | Watanabe, M. | Yokoyama, S. | GUN | MG | ZN | (alpha/beta)8 barrel | Riken structural genomics/proteomics initiative | Rsgi | Structural genomics
