※ FF family introduction

    FF domains were first identified in the murine splicing factor FBP11 (formin-binding protein 11) as a repeated sequence of about 60 amino acids containing two conserved phenylalanine (F) residues that give name to the domain. FF domains are primarily present in only the following three proteins: Prp40, FBP11, and CA150. Most interestingly, Prp40, FBP11, and CA150 have all been shown to recognize phospho-CTD-RNAPII repeats through their FF domains (1).

Reference
1. Gasch, A. (2006) The structure of Prp40 FF1 domain and its interaction with the crn-TPR1 motif of Clf1 gives a new insight into the binding mode of FF domains . J Biol Chem, 281, 356-64. PMID: 16253993