Term Name:	U12-type precatalytic spliceosome
Synonyms:	AT-AC precatalytic spliceosome, mammalian U12-type spliceosomal complex B, mammalian U12-type spliceosomal complex B1, minor precatalytic spliceosome, yeast U12-type spliceosomal complex A2-1
Definition:	A spliceosomal complex that is formed by the recruitment of the preassembled U4atac/U6atac.U5 tri-snRNP to the U12-type prespliceosome. Although all 5 snRNPs are present, the precatalytic spliceosome is catalytically inactive. The precatalytic spliceosome includes many proteins in addition to those found in the U11, U12 and U4atac/U6atac.U5 snRNPs.
Ontology:	GO: Cellular Component [GO:0071016]    QuickGO    AmiGO