1zar: Difference between revisions
New page: left|200px<br /><applet load="1zar" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zar, resolution 1.75Å" /> '''Crystal Structure of... |
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[[Image:1zar.gif|left|200px]]<br /><applet load="1zar" size=" | [[Image:1zar.gif|left|200px]]<br /><applet load="1zar" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1zar, resolution 1.75Å" /> | caption="1zar, resolution 1.75Å" /> | ||
'''Crystal Structure of A.fulgidus Rio2 Kinase Complexed With ADP and Manganese Ions'''<br /> | '''Crystal Structure of A.fulgidus Rio2 Kinase Complexed With ADP and Manganese Ions'''<br /> | ||
==Overview== | ==Overview== | ||
The highly conserved, atypical RIO serine protein kinases are found in all | The highly conserved, atypical RIO serine protein kinases are found in all organisms, from archaea to man. In yeast, the kinase activity of Rio2 is necessary for the final processing step of maturing the 18S ribosomal rRNA. We have previously shown that the Rio2 protein from Archaeoglobus fulgidus contains both a small kinase domain and an N-terminal winged helix domain. Previously solved structures using crystals soaked in nucleotides and Mg2+ or Mn2+ showed bound nucleotide but no ordered metal ions, leading us to the conclusion that they did not represent an active conformation of the enzyme. To determine the functional form of Rio2, we crystallized it after incubation with ATP or ADP and Mn2+. Co-crystal structures of Rio2-ATP-Mn and Rio2-ADP-Mn were solved at 1.84 and 1.75 angstroms resolution, respectively. The gamma-phosphate of ATP is firmly positioned in a manner clearly distinct from its location in canonical serine kinases. Comparison of the Rio2-ATP-Mn complex with the Rio2 structure with no added nucleotides and with the ADP complex indicates that a flexible portion of the Rio2 molecule becomes ordered through direct interaction between His126 and the gamma-phosphate oxygen of ATP. Phosphopeptide mapping of the autophosphorylation site of Rio2 identified Ser128, within the flexible loop and directly adjacent to the part that becomes ordered in response to ATP, as the target. These results give us further information about the nature of the active site of Rio2 kinase and suggest a mechanism of regulation of its enzymatic activity. | ||
==About this Structure== | ==About this Structure== | ||
1ZAR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus Archaeoglobus fulgidus] with MN, ADP and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1ZAR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus Archaeoglobus fulgidus] with <scene name='pdbligand=MN:'>MN</scene>, <scene name='pdbligand=ADP:'>ADP</scene> and <scene name='pdbligand=EDO:'>EDO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZAR OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: winged-helix]] | [[Category: winged-helix]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:13:43 2008'' | ||
Revision as of 17:13, 21 February 2008
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Crystal Structure of A.fulgidus Rio2 Kinase Complexed With ADP and Manganese Ions
OverviewOverview
The highly conserved, atypical RIO serine protein kinases are found in all organisms, from archaea to man. In yeast, the kinase activity of Rio2 is necessary for the final processing step of maturing the 18S ribosomal rRNA. We have previously shown that the Rio2 protein from Archaeoglobus fulgidus contains both a small kinase domain and an N-terminal winged helix domain. Previously solved structures using crystals soaked in nucleotides and Mg2+ or Mn2+ showed bound nucleotide but no ordered metal ions, leading us to the conclusion that they did not represent an active conformation of the enzyme. To determine the functional form of Rio2, we crystallized it after incubation with ATP or ADP and Mn2+. Co-crystal structures of Rio2-ATP-Mn and Rio2-ADP-Mn were solved at 1.84 and 1.75 angstroms resolution, respectively. The gamma-phosphate of ATP is firmly positioned in a manner clearly distinct from its location in canonical serine kinases. Comparison of the Rio2-ATP-Mn complex with the Rio2 structure with no added nucleotides and with the ADP complex indicates that a flexible portion of the Rio2 molecule becomes ordered through direct interaction between His126 and the gamma-phosphate oxygen of ATP. Phosphopeptide mapping of the autophosphorylation site of Rio2 identified Ser128, within the flexible loop and directly adjacent to the part that becomes ordered in response to ATP, as the target. These results give us further information about the nature of the active site of Rio2 kinase and suggest a mechanism of regulation of its enzymatic activity.
About this StructureAbout this Structure
1ZAR is a Single protein structure of sequence from Archaeoglobus fulgidus with , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Autophosphorylation of Archaeoglobus fulgidus Rio2 and crystal structures of its nucleotide-metal ion complexes., LaRonde-LeBlanc N, Guszczynski T, Copeland T, Wlodawer A, FEBS J. 2005 Jun;272(11):2800-10. PMID:15943813
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