passages.id: split_5_test_1810_passage
passages.type: progene_text
passages.text: C(2)H(2) - type zinc finger domains mediate the integration of SF3a60 and SF3a66 into the U2 snRNP , and we propose a model in which protein - protein interactions between the zinc finger domains and the Sm proteins , common to all spliceosomal snRNPs , contribute to the assembly of the 17S U2 snRNP .