1jri
From Proteopedia
(New page: 200px<br /><applet load="1jri" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jri, resolution 2.80Å" /> '''The Crystal Structur...) |
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| - | [[Image:1jri.gif|left|200px]]<br /><applet load="1jri" size=" | + | [[Image:1jri.gif|left|200px]]<br /><applet load="1jri" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1jri, resolution 2.80Å" /> | caption="1jri, resolution 2.80Å" /> | ||
'''The Crystal Structure of an Sm-like Archaeal Protein with Two Heptamers in the Asymmetric Unit.'''<br /> | '''The Crystal Structure of an Sm-like Archaeal Protein with Two Heptamers in the Asymmetric Unit.'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Intron splicing is a prime example of the many types of RNA processing | + | Intron splicing is a prime example of the many types of RNA processing catalyzed by small nuclear ribonucleoprotein (snRNP) complexes. Sm proteins form the cores of most snRNPs, and thus to learn principles of snRNP assembly we characterized the oligomerization and ligand-binding properties of Sm-like archaeal proteins (SmAPs) from Pyrobaculum aerophilum (Pae) and Methanobacterium thermautotrophicum (Mth). Ultracentrifugation shows that Mth SmAP1 is exclusively heptameric in solution, whereas Pae SmAP1 forms either disulfide-bonded 14-mers or sub-heptameric states (depending on the redox potential). By electron microscopy, we show that Pae and Mth SmAP1 polymerize into bundles of well ordered fibers that probably form by head-to-tail stacking of heptamers. The crystallographic results reported here corroborate these findings by showing heptamers and 14-mers of both Mth and Pae SmAP1 in four new crystal forms. The 1.9 A-resolution structure of Mth SmAP1 bound to uridine-5'-monophosphate (UMP) reveals conserved ligand-binding sites. The likely RNA binding site in Mth agrees with that determined for Archaeoglobus fulgidus (Afu) SmAP1. Finally, we found that both Pae and Mth SmAP1 gel-shift negatively supercoiled DNA. These results distinguish SmAPs from eukaryotic Sm proteins and suggest that SmAPs have a generic single-stranded nucleic acid-binding activity. |
==About this Structure== | ==About this Structure== | ||
| - | 1JRI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanothermobacter_thermautotrophicus Methanothermobacter thermautotrophicus] with CL and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1JRI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanothermobacter_thermautotrophicus Methanothermobacter thermautotrophicus] with <scene name='pdbligand=CL:'>CL</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=1JRI OCA]. |
==Reference== | ==Reference== | ||
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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 13:25:54 2008'' |
Revision as of 11:25, 21 February 2008
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The Crystal Structure of an Sm-like Archaeal Protein with Two Heptamers in the Asymmetric Unit.
Overview
Intron splicing is a prime example of the many types of RNA processing catalyzed by small nuclear ribonucleoprotein (snRNP) complexes. Sm proteins form the cores of most snRNPs, and thus to learn principles of snRNP assembly we characterized the oligomerization and ligand-binding properties of Sm-like archaeal proteins (SmAPs) from Pyrobaculum aerophilum (Pae) and Methanobacterium thermautotrophicum (Mth). Ultracentrifugation shows that Mth SmAP1 is exclusively heptameric in solution, whereas Pae SmAP1 forms either disulfide-bonded 14-mers or sub-heptameric states (depending on the redox potential). By electron microscopy, we show that Pae and Mth SmAP1 polymerize into bundles of well ordered fibers that probably form by head-to-tail stacking of heptamers. The crystallographic results reported here corroborate these findings by showing heptamers and 14-mers of both Mth and Pae SmAP1 in four new crystal forms. The 1.9 A-resolution structure of Mth SmAP1 bound to uridine-5'-monophosphate (UMP) reveals conserved ligand-binding sites. The likely RNA binding site in Mth agrees with that determined for Archaeoglobus fulgidus (Afu) SmAP1. Finally, we found that both Pae and Mth SmAP1 gel-shift negatively supercoiled DNA. These results distinguish SmAPs from eukaryotic Sm proteins and suggest that SmAPs have a generic single-stranded nucleic acid-binding activity.
About this Structure
1JRI is a Single protein structure of sequence from Methanothermobacter thermautotrophicus with and as ligands. Full crystallographic information is available from OCA.
Reference
The oligomerization and ligand-binding properties of Sm-like archaeal proteins (SmAPs)., Mura C, Kozhukhovsky A, Gingery M, Phillips M, Eisenberg D, Protein Sci. 2003 Apr;12(4):832-47. PMID:12649441
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