1i9t: Difference between revisions

Revision as of 19:45, 2 May 2008

CRYSTAL STRUCTURE OF THE OXIDIZED RNA TRIPHOSPHATASE DOMAIN OF MOUSE MRNA CAPPING ENZYME

OverviewOverview

The 5' capping of mammalian pre-mRNAs is initiated by RNA triphosphatase, a member of the cysteine phosphatase superfamily. Here we report the 1.65 A crystal structure of mouse RNA triphosphatase, which reveals a deep, positively charged active site pocket that can fit a 5' triphosphate end. Structural, biochemical and mutational results show that despite sharing an HCxxxxxR(S/T) motif, a phosphoenzyme intermediate and a core alpha/beta-fold with other cysteine phosphatases, the mechanism of phosphoanhydride cleavage by mammalian capping enzyme differs from that used by protein phosphatases to hydrolyze phosphomonoesters. The most significant difference is the absence of a carboxylate general acid catalyst in RNA triphosphatase. Residues conserved uniquely among the RNA phosphatase subfamily are important for function in cap formation and are likely to play a role in substrate recognition.

About this StructureAbout this Structure

1I9T is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.

ReferenceReference

Structure and mechanism of the RNA triphosphatase component of mammalian mRNA capping enzyme., Changela A, Ho CK, Martins A, Shuman S, Mondragon A, EMBO J. 2001 May 15;20(10):2575-86. PMID:11350947 Page seeded by OCA on Fri May 2 19:45:04 2008

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OCA

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 [[Image:1i9t.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1i9t |SIZE=350|CAPTION= <scene name='initialview01'>1i9t</scene>, resolution 1.7&Aring;
+The line below this paragraph, containing "STRUCTURE_1i9t", 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=CAC:CACODYLATE+ION'>CAC</scene>, <scene name='pdbligand=CSO:S-HYDROXYCYSTEINE'>CSO</scene>, <scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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/Polynucleotide_5'-phosphatase Polynucleotide 5'-phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.33 3.1.3.33] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1i9t|  PDB=1i9t  |  SCENE=  }}
-|RELATEDENTRY=[[1i9s|1I9S]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1i9t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i9t OCA], [http://www.ebi.ac.uk/pdbsum/1i9t PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1i9t RCSB]</span>
-}}
 '''CRYSTAL STRUCTURE OF THE OXIDIZED RNA TRIPHOSPHATASE DOMAIN OF MOUSE MRNA CAPPING ENZYME'''
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 [[Category: Mondragon, A.]]
 [[Category: Shuman, S.]]
-[[Category: cysteine sulfenic acid]]
+[[Category: Cysteine sulfenic acid]]
-[[Category: mrna capping enzyme]]
+[[Category: Mrna capping enzyme]]
-[[Category: rna triphosphatase domain]]
+[[Category: Rna triphosphatase domain]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 19:45:04 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:16:42 2008''