U12-type prespliceosome
A spliceosomal complex that is formed by the cooperative binding of the heterodimeric U11/U12 snRNP to the 5' splice site and the branch point sequence. The U12-type prespliceosome includes many proteins in addition to those found in the U11/U12 heterodimeric snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation.
GO:0005689
U12-type spliceosomal complex
is_a
GO:0071010
prespliceosome
is_a
AT-AC prespliceosome
narrow
mammalian U12-type spliceosomal complex A
narrow
minor prespliceosome
exact
yeast U12-type spliceosomal complex B
narrow