The crystal structure of a heptameric archaeal Sm protein: Implications for the eukaryotic snRNP core
- 8 May 2001
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 98 (10) , 5532-5537
- https://doi.org/10.1073/pnas.091102298
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-Å 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.Keywords
This publication has 42 references indexed in Scilit:
- The C-terminal RG Dipeptide Repeats of the Spliceosomal Sm Proteins D1 and D3 Contain Symmetrical Dimethylarginines, Which Form a Major B-cell Epitope for Anti-Sm AutoantibodiesJournal of Biological Chemistry, 2000
- Transproteomic evidence of a loop-deletion mechanism for enhancing protein thermostabilityJournal of Molecular Biology, 1999
- Role of Methionine 56 in the Control of the Oxidation−Reduction Potentials of theClostridiumbeijerinckiiFlavodoxin: Effects of Substitutions by Aliphatic Amino Acids and Evidence for a Role of Sulfur−Flavin InteractionsBiochemistry, 1998
- Gapped BLAST and PSI-BLAST: a new generation of protein database search programsNucleic Acids Research, 1997
- [20] Processing of X-ray diffraction data collected in oscillation modePublished by Elsevier ,1997
- The CCP4 suite: programs for protein crystallographyActa Crystallographica Section D-Biological Crystallography, 1994
- SETOR: Hardware-lighted three-dimensional solid model representations of macromoleculesJournal of Molecular Graphics, 1993
- Main-chain Bond Lengths and Bond Angles in Protein StructuresJournal of Molecular Biology, 1993
- Phosphocholine binding immunoglobulin Fab McPC603Journal of Molecular Biology, 1986
- Sulphur‐aromatic interactions in proteinsFEBS Letters, 1985