Structural highlights
4w92 is a 2 chain structure with sequence from Bacillus subtilis and Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Method: | X-ray diffraction, Resolution 3.209Å |
| Ligands: | , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
SNRPA_HUMAN Binds stem loop II of U1 snRNA. It is the first snRNP to interact with pre-mRNA. This interaction is required for the subsequent binding of U2 snRNP and the U4/U6/U5 tri-snRNP. In a snRNP-free form (SF-A) may be involved in coupled pre-mRNA splicing and polyadenylation process. Binds preferentially to the 5'-UGCAC-3' motif in vitro.[1]
Publication Abstract from PubMed
Cyclic diadenosine monophosphate (c-di-AMP) is a second messenger that is essential for growth and homeostasis in bacteria. A recently discovered c-di-AMP-responsive riboswitch controls the expression of genes in a variety of bacteria, including important pathogens. To elucidate the molecular basis for specific binding of c-di-AMP by a gene-regulatory mRNA domain, we have determined the co-crystal structure of this riboswitch. Unexpectedly, the structure reveals an internally pseudo-symmetric RNA in which two similar three-helix-junction elements associate head-to-tail, creating a trough that cradles two c-di-AMP molecules making quasi-equivalent contacts with the riboswitch. The riboswitch selectively binds c-di-AMP and discriminates exquisitely against other cyclic dinucleotides, such as c-di-GMP and cyclic-AMP-GMP, via interactions with both the backbone and bases of its cognate second messenger. Small-angle X-ray scattering experiments indicate that global folding of the riboswitch is induced by the two bound cyclic dinucleotides, which bridge the two symmetric three-helix domains. This structural reorganization likely couples c-di-AMP binding to gene expression.
Crystal structure of a c-di-AMP riboswitch reveals an internally pseudo-dimeric RNA.,Jones CP, Ferre-D'Amare AR EMBO J. 2014 Sep 30. pii: e201489209. PMID:25271255[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Lutz CS, Cooke C, O'Connor JP, Kobayashi R, Alwine JC. The snRNP-free U1A (SF-A) complex(es): identification of the largest subunit as PSF, the polypyrimidine-tract binding protein-associated splicing factor. RNA. 1998 Dec;4(12):1493-9. PMID:9848648
- ↑ Jones CP, Ferre-D'Amare AR. Crystal structure of a c-di-AMP riboswitch reveals an internally pseudo-dimeric RNA. EMBO J. 2014 Sep 30. pii: e201489209. PMID:25271255 doi:http://dx.doi.org/10.15252/embj.201489209
