1lnx: Difference between revisions
New page: left|200px<br /><applet load="1lnx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lnx, resolution 2.05Å" /> '''Crystal structure of... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1lnx.gif|left|200px]]<br /><applet load="1lnx" size=" | [[Image:1lnx.gif|left|200px]]<br /><applet load="1lnx" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1lnx, resolution 2.05Å" /> | caption="1lnx, resolution 2.05Å" /> | ||
'''Crystal structure of the P.aerophilum SmAP1 heptamer in a new crystal form (C2221)'''<br /> | '''Crystal structure of the P.aerophilum SmAP1 heptamer in a new crystal form (C2221)'''<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== | ||
1LNX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrobaculum_aerophilum Pyrobaculum aerophilum] with URI, ACY and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1LNX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrobaculum_aerophilum Pyrobaculum aerophilum] with <scene name='pdbligand=URI:'>URI</scene>, <scene name='pdbligand=ACY:'>ACY</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LNX OCA]. | ||
==Reference== | ==Reference== | ||
| Line 21: | Line 21: | ||
[[Category: beta barrel-like structure (ob fold); homoheptameric]] | [[Category: beta barrel-like structure (ob fold); homoheptameric]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:46:41 2008'' | ||
Revision as of 14:46, 21 February 2008
|
Crystal structure of the P.aerophilum SmAP1 heptamer in a new crystal form (C2221)
OverviewOverview
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 StructureAbout this Structure
1LNX is a Single protein structure of sequence from Pyrobaculum aerophilum with , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
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
Page seeded by OCA on Thu Feb 21 13:46:41 2008