Serine/Arginine Rich Splicing Factor 3 (SRSF3)

The SR family of mRNA splicing factors was so designated because SR proteins contain sequences of consecutive serine (S) and arginine (R) dipeptides. By searching a sequence database with the partial protein sequence of SRp20, the authors found that a previously identified cDNA, X16, encoded mouse SRp20.

The predicted 164-amino acid mouse and human proteins are identical. The sequence of the SRp20 protein is related to those of the other SR proteins identified; all contain 1 or 2 copies of an N-terminal repeat (A and B) spaced by a series of glycine residues that may form a flexible hinge, followed by a C-terminal SR domain. The A repeat contains an RNA recognition motif (RRM). SRp20 and SRp30b contain repeat A only.