RNA binding motif protein 17, also known as RBM17, is splice factor that binds to the single stranded 3'AG at the exon/intron border and promotes its utilization in the second catalytic step. This protein is involved in the regulation of alternative splicing and the utilization of cryptic splice sites. This protein promotes the utilization of a cryptic splice site created by the beta-110 mutation in the HBB gene. The resulting frameshift leads to sickle cell anemia. Recombinant human RBM17 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.