1ljo
From Proteopedia
(New page: 200px<br /><applet load="1ljo" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ljo, resolution 1.95Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1ljo.jpg|left|200px]]<br /><applet load="1ljo" size=" | + | [[Image:1ljo.jpg|left|200px]]<br /><applet load="1ljo" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ljo, resolution 1.95Å" /> | caption="1ljo, resolution 1.95Å" /> | ||
'''CRYSTAL STRUCTURE OF AN SM-LIKE PROTEIN (AF-SM2) FROM ARCHAEOGLOBUS FULGIDUS AT 1.95A RESOLUTION'''<br /> | '''CRYSTAL STRUCTURE OF AN SM-LIKE PROTEIN (AF-SM2) FROM ARCHAEOGLOBUS FULGIDUS AT 1.95A RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Proteins of largely unknown function related to the Sm proteins present in | + | Proteins of largely unknown function related to the Sm proteins present in the core domain of eukaryotic small nuclear ribonucleoprotein particles have recently been detected in Archaea. In contrast to eukaryotes, Archaea contain maximally two distinct Sm-related proteins belonging to different subfamilies, we refer to as Sm1 and Sm2. Here we report the crystal structures of the Sm1- and Sm2-type proteins from the hyperthermophilic euryarchaeon Archaeoglobus fulgidus (AF-Sm1 and AF-Sm2) at a resolution of 2.5 and 1.95 A, respectively. While the AF-Sm1 protein forms a heptameric ring structure similar to that found in other archaeal Sm1-type proteins, the AF-Sm2 protein unexpectedly forms a homo-hexamer in the crystals, and, as is evident from the mass spectrometric analysis, also in solution. Both proteins have essentially the same monomer fold and inter-subunit beta-sheet hydrogen bonding giving rise to a similar overall architecture of the doughnut-shaped six and seven-membered rings. In addition, a conserved uracil-binding pocket identified previously in an AF-Sm1/RNA complex, suggests a common RNA-binding mode for the AF-Sm1 and AF-Sm2 proteins, in line with solution studies showing preferential binding to U-rich oligonucleotides for both proteins. Clear differences are however seen in the charge distribution within the two structures. The rough faces of the rings, i.e. the faces not containing the base binding pockets, have opposite charges in the two structures, being predominantly positive in AF-Sm1 and negative in AF-Sm2. Differences in the ionic interactions between subunits provide an explanation for the distinctly different oligomerisation behaviour of the AF-Sm1 and AF-Sm2 proteins and of Sm1- and Sm2-type proteins in general, as well as the stability of their complexes. Implications for the functions of archaeal Sm proteins are being discussed. |
==About this Structure== | ==About this Structure== | ||
| - | 1LJO 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 CD and ACY as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1LJO 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=CD:'>CD</scene> and <scene name='pdbligand=ACY:'>ACY</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LJO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: snrnp]] | [[Category: snrnp]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:45:31 2008'' |
Revision as of 11:45, 21 February 2008
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CRYSTAL STRUCTURE OF AN SM-LIKE PROTEIN (AF-SM2) FROM ARCHAEOGLOBUS FULGIDUS AT 1.95A RESOLUTION
Overview
Proteins of largely unknown function related to the Sm proteins present in the core domain of eukaryotic small nuclear ribonucleoprotein particles have recently been detected in Archaea. In contrast to eukaryotes, Archaea contain maximally two distinct Sm-related proteins belonging to different subfamilies, we refer to as Sm1 and Sm2. Here we report the crystal structures of the Sm1- and Sm2-type proteins from the hyperthermophilic euryarchaeon Archaeoglobus fulgidus (AF-Sm1 and AF-Sm2) at a resolution of 2.5 and 1.95 A, respectively. While the AF-Sm1 protein forms a heptameric ring structure similar to that found in other archaeal Sm1-type proteins, the AF-Sm2 protein unexpectedly forms a homo-hexamer in the crystals, and, as is evident from the mass spectrometric analysis, also in solution. Both proteins have essentially the same monomer fold and inter-subunit beta-sheet hydrogen bonding giving rise to a similar overall architecture of the doughnut-shaped six and seven-membered rings. In addition, a conserved uracil-binding pocket identified previously in an AF-Sm1/RNA complex, suggests a common RNA-binding mode for the AF-Sm1 and AF-Sm2 proteins, in line with solution studies showing preferential binding to U-rich oligonucleotides for both proteins. Clear differences are however seen in the charge distribution within the two structures. The rough faces of the rings, i.e. the faces not containing the base binding pockets, have opposite charges in the two structures, being predominantly positive in AF-Sm1 and negative in AF-Sm2. Differences in the ionic interactions between subunits provide an explanation for the distinctly different oligomerisation behaviour of the AF-Sm1 and AF-Sm2 proteins and of Sm1- and Sm2-type proteins in general, as well as the stability of their complexes. Implications for the functions of archaeal Sm proteins are being discussed.
About this Structure
1LJO is a Single protein structure of sequence from Archaeoglobus fulgidus with and as ligands. Full crystallographic information is available from OCA.
Reference
Archaeal Sm proteins form heptameric and hexameric complexes: crystal structures of the Sm1 and Sm2 proteins from the hyperthermophile Archaeoglobus fulgidus., Toro I, Basquin J, Teo-Dreher H, Suck D, J Mol Biol. 2002 Jun 28;320(1):129-42. PMID:12079339
Page seeded by OCA on Thu Feb 21 13:45:31 2008
Categories: Archaeoglobus fulgidus | Single protein | Basquin, J. | Suck, D. | Teo-Dreher, H. | Toro, I. | ACY | CD | Core snrnp domain | Rna binding protein | Sm | Snrnp
