The U2/U6 snRNA complex is a conserved and essential component of the active spliceosome that interacts with the pre-mRNA substrate and essential protein splicing factors to promote splicing catalysis. Here we have elucidated the solution structure of a 111-nucleotide U2/U6 complex using an approach that integrates SAXS, NMR, and molecular modeling. The U2/U6 structure contains a three-helix junction that forms an extended "Y" shape. The U6 internal stem-loop (ISL) forms a continuous stack with U2/U6 Helices Ib, Ia, and III. The coaxial stacking of Helix Ib on the U6 ISL is a configuration that is similar to the Domain V structure in group II introns. Interestingly, essential features of the complex-including the U80 metal binding site, AGC triad, and pre-mRNA recognition sites-localize to one face of the molecule. This observation suggests that the U2/U6 structure is well-suited for orienting substrate and cofactors during splicing catalysis.
PDB ID: 2LK3Download
MMDB ID: 97363
PDB Deposition Date: 2011/10/3
Updated in MMDB: 2012/04
Experimental Method:
solution nmr
Source Organism:
Biological Unit for 2LK3: monomeric; determined by author
Molecular Components in 2LK3
Label Count Molecule
Nucleotide(1 molecule)
RNA (5'- R(*gp*gp*cp*up*up*ap*gp*ap*up*cp*ap*gp*ap*ap*ap*up*gp*ap*up*cp*ap*gp* Cp*c)-3')
Molecule annotation
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