Send to

Choose Destination
See comment in PubMed Commons below
Mol Cell. 1997 Dec;1(1):151-60.

Terminal intron dinucleotide sequences do not distinguish between U2- and U12-dependent introns.

Author information

Department of Molecular Biology, Lerner Research Institute, Cleveland Clinic Foundation, Ohio 44195, USA.


Two types of eukaryotic nuclear introns are known: the common U2-dependent class with /GU and AG/ terminal intron dinucleotides, and the rare U12-dependent class with /AU and AC/ termini. Here we show that the U12-dependent splicing system can splice introns with /GU and AG/ termini and that such introns occur naturally. Further, U2-dependent introns with /AU and AC/termini also occur naturally and are evolutionarily conserved. Thus, the sequence of the terminal dinucleotides does not determine which spliceosomal system removes an intron. Rather, the four classes of introns described here can be sorted into two mechanistic classes (U2- or U12-dependent) by inspection of the complete set of conserved splice site sequences.

[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons


    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center