The canonical GU dinucleotide at the 5' splice site is recognized by p220 of the U5 snRNP within the spliceosome.
Specific recognition of the 5' splice site (5'SS) by the spliceosome components was studied using a simple in vitro system in which a short 5'SS RNA oligonucleotide specifically induces the assembly of snRNP particles into spliceosome-like complexes and actively participates in a trans-splicing reaction. Short-range cross-liking demonstrates that a U5 snRNP protein component, p220 (the human analogue of the yeast Prp8) specifically interacts with the invariant GU dinucleotide at the 5' end of the intron. The GU:p220 interaction can be detected in the functional splicing complex B. Although p220 has been known to contact several nucleotides around the 5' splice junction, the p220:GU dinucleotide interaction described here is remarkably specific. Consistent with the high conservation of the GU, even minor modifications of this element affect recognition of the 5'SS RNA by p220. Substitution of uridine at the GU with base analogues containing a large methyl or iodo group, but not a smaller flouro group at base position 5, interferes with association of 5'SS RNA with snRNP complexes and their functional participation in splicing.
Reyes
J L
JL
Rockefeller University, New York, New York 10021, USA.
Kois
P
P
Konforti
B B
BB
Konarska
M M
MM
D001483:Base Sequence; D017124:Conserved Sequence; D003432:Cross-Linking Reagents; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009843:Oligoribonucleotides / Q000378:metabolism; D011485:Protein Binding; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing / Q000502:physiology*; D017415:Ribonucleoprotein, U5 Small Nuclear / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D017381:Spliceosomes / Q000378:metabolism*; D013891:Thiouridine / Q000378:metabolism; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D009843:Oligoribonucleotides; D012322:RNA Precursors; D017415:Ribonucleoprotein, U5 Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; D013891:Thiouridine