Figure 3

Solution structure of an SR protein RRM from human SRp20 (blue) in complex with the RNA sequence 5'-CAUC-3' (red). All four nucleotides present are contacted by the RRM, but only the 5' cytosine is recognized specifically. The structure was generated using the Visual Molecular Dynamics program [78] from coordinates deposited in the Brookhaven National Laboratory Protein Data Bank [30].