Predicted to enable mRNA binding activity. Predicted to be involved in mRNA splicing, via spliceosome. Part of catalytic step 2 spliceosome and precatalytic spliceosome. Is expressed in several structures, including CNS glial cell; embryonic/larval midgut primordium; ganglia; head epidermis primordium; and somatic trunk mesoderm derivative. Orthologous to human SF3B6 (splicing factor 3b subunit 6).