go_id,ontology,go_term,term_definition,evidence GO:0000166,MF,"nucleotide binding","Interacting selectively and non-covalently with a nucleotide, any compound consisting of a nucleoside that is esterified with (ortho)phosphate or an oligophosphate at any hydroxyl group on the ribose or deoxyribose.",IEA GO:0000398,BP,"mRNA splicing, via spliceosome","The joining together of exons from one or more primary transcripts of messenger RNA (mRNA) and the excision of intron sequences, via a spliceosomal mechanism, so that mRNA consisting only of the joined exons is produced.",IGI GO:0001825,BP,"blastocyst formation","The initial formation of a blastocyst from a solid ball of cells known as a morula.",IEA GO:0005654,CC,nucleoplasm,"That part of the nuclear content other than the chromosomes or the nucleolus.",IDA GO:0005684,CC,"U2-type spliceosomal complex","Any spliceosomal complex that forms during the splicing of a messenger RNA primary transcript to excise an intron that has canonical consensus sequences near the 5' and 3' ends.",IC GO:0005686,CC,"U2 snRNP","A ribonucleoprotein complex that contains small nuclear RNA U2.",TAS GO:0005689,CC,"U12-type spliceosomal complex","Any spliceosomal complex that forms during the splicing of a messenger RNA primary transcript to excise an intron; the series of U12-type spliceosomal complexes is involved in the splicing of the majority of introns that contain atypical AT-AC terminal dinucleotides, as well as other non-canonical introns. The entire splice site signal, not just the terminal dinucleotides, is involved in determining which spliceosome utilizes the site.",IDA GO:0044822,MF,"poly(A) RNA binding","Interacting non-covalently with a poly(A) RNA, a RNA molecule which has a tail of adenine bases.",IDA GO:0071011,CC,"precatalytic spliceosome","A spliceosomal complex that is formed by the recruitment of a preassembled U5-containing tri-snRNP to the 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 associated snRNPs.",IBA GO:0071013,CC,"catalytic step 2 spliceosome","A spliceosomal complex that contains three snRNPs, including U5, bound to a splicing intermediate in which the first catalytic cleavage of the 5' splice site has occurred. The precise subunit composition differs significantly from that of the catalytic step 1, or activated, spliceosome, and includes many proteins in addition to those found in the associated snRNPs.",IDA