1I8F

THE CRYSTAL STRUCTURE OF A HEPTAMERIC ARCHAEAL SM PROTEIN: IMPLICATIONS FOR THE EUKARYOTIC SNRNP CORE

Summary for 1I8F

• Entry DOI: 10.2210/pdb1i8f/pdb
• Related: 1B34 1D3B
• Descriptor: PUTATIVE SNRNP SM-LIKE PROTEIN, GLYCEROL (3 entities in total)
• Functional Keywords: beta barrel-like smap monomers form 35-stranded beta-sheet in the heptamer, structural genomics
• Biological source: Pyrobaculum aerophilum
• Total number of polymer chains: 7
• Total formula weight: 63021.37

Authors

Mura, C.,Cascio, D.,Sawaya, M.R.,Eisenberg, D. (deposition date: 2001-03-14, release date: 2001-05-16, Last modification date: 2024-02-07)

Primary citation

Mura, C.,Cascio, D.,Sawaya, M.R.,Eisenberg, D.S.
The crystal structure of a heptameric archaeal Sm protein: Implications for the eukaryotic snRNP core.
Proc.Natl.Acad.Sci.USA, 98:5532-5537, 2001

PubMed Abstract: 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.

PubMed: 11331747
DOI: 10.1073/pnas.091102298

Experimental method

X-RAY DIFFRACTION (1.75 Å)