RS domain-splicing signal interactions in splicing of U12-type and U2-type introns
Program in Molecular Medicine; Program in Gene Function and Expression
Medical Subject Headings
Base Sequence; Exons; Hela Cells; Humans; *Introns; Molecular Sequence Data; Nuclear Proteins; Protein Structure, Tertiary; RNA Splice Sites; *RNA Splicing; RNA, Small Nuclear; RNA-Binding Proteins; Spliceosomes
Genetics and Genomics
Serine-arginine (SR) proteins are general metazoan splicing factors that contain an essential arginine/serine-rich (RS) domain. On typical U2-type introns, RS domains contact the branchpoint and 5' splice site to promote base-pairing with U small nuclear RNAs (snRNAs). Here we analyze the role of SR proteins in splicing of U12-type introns and in the second step of U2-type intron splicing. We show that RS domains contact the branchpoint and 5' splice site of a U12-type intron. On a U2-type intron, we find that the RS domain contacts the site of the U6 snRNA-5' splice site interaction during the first step of splicing and shifts to contact the site of the U5 snRNA-exon 1 interaction during the second step. Our results reveal alternative interactions between the RS domain and 5' splice site region that coincide with remodeling of the spliceosome between the two catalytic steps.
Rights and Permissions
Citation: Nat Struct Mol Biol. 2007 Jul;14(7):597-603. Epub 2007 Jul 1. Link to article on publisher's site