1iq8: Difference between revisions

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Revision as of 21:23, 30 March 2008

File:1iq8.jpg

, resolution 2.2Å

Ligands:

,

Activity:

Queuine tRNA-ribosyltransferase, with EC number 2.4.2.29

Resources:

FirstGlance, OCA, PDBsum, RCSB

Coordinates:

save as pdb, mmCIF, xml

Crystal Structure of archaeosine tRNA-guanine transglycosylase from Pyrococcus horikoshii

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

1IQ8 is a Single protein structure of sequence from Pyrococcus horikoshii. 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

Page seeded by OCA on Sun Mar 30 21:23:04 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 4: / Line 4: @@
 |PDB= 1iq8 |SIZE=350|CAPTION= <scene name='initialview01'>1iq8</scene>, resolution 2.2&Aring;
 |SITE=
-|LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> and <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene>
+|LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene>
-|ACTIVITY= [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]
+|ACTIVITY= <span class='plainlinks'>[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] </span>
 |GENE=
+|DOMAIN=
+|RELATEDENTRY=
+|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1iq8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1iq8 OCA], [http://www.ebi.ac.uk/pdbsum/1iq8 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1iq8 RCSB]</span>
 }}
@@ Line 35: / Line 38: @@
 [[Category: Watanabe, M.]]
 [[Category: Yokoyama, S.]]
-[[Category: MG]]
-[[Category: ZN]]
 [[Category: (alpha/beta)8 barrel]]
 [[Category: riken structural genomics/proteomics initiative]]
@@ Line 42: / Line 43: @@
 [[Category: structural genomic]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:53:26 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:23:04 2008''