1i8f | pdb_00001i8f
THE CRYSTAL STRUCTURE OF A HEPTAMERIC ARCHAEAL SM PROTEIN: IMPLICATIONS FOR THE EUKARYOTIC SNRNP CORE
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| 1i8f, resolution 1.75Å | |||||||||||||
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| Ligands: | GOL | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
Overview
Sm proteins form the core of small nuclear ribonucleoprotein particles (snRNPs), making them key components of several mRNA-processing assemblies, including the spliceosome. We report the 1.75-A crystal structure of SmAP, an Sm-like archaeal protein that forms a heptameric ring perforated by a cationic pore. In addition to providing direct evidence for such an assembly in eukaryotic snRNPs, this structure (i) shows that SmAP homodimers are structurally similar to human Sm heterodimers, (ii) supports a gene duplication model of Sm protein evolution, and (iii) offers a model of SmAP bound to single-stranded RNA (ssRNA) that explains Sm binding-site specificity. The pronounced electrostatic asymmetry of the SmAP surface imparts directionality to putative SmAP-RNA interactions.
About this Structure
1I8F is a Single protein structure of sequence from Pyrobaculum aerophilum. Full crystallographic information is available from OCA.
Reference
The crystal structure of a heptameric archaeal Sm protein: Implications for the eukaryotic snRNP core., Mura C, Cascio D, Sawaya MR, Eisenberg DS, Proc Natl Acad Sci U S A. 2001 May 8;98(10):5532-7. Epub 2001 May 1. PMID:11331747
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