why CLIP-seq for SRSF1's binding sites didn't locate in the branch point but in the exons

Question

[li487]

I check the CLIP-seq data for SRSF1. I learned from the book that SRSF1 bind the branch point sites to init splicing. But the result showed that almost all the binding sites are in the exon region, but not in the branch point region. so why?

[Eric Lim]

SRSF1 binds to sequences of exonic splicing enhancers (ESEs) to regulate splicing, so why wouldn't you expect the enrichment to cluster in the exons?

[li487]

I expect SRSF1 should enrich in both exons and branch sites.