Figure 1.

Prp8 forms extensive cross-links to RNA residues in the intron consensus sequences, and in the 5′ and 3′ exons. Intron consensus sequences that define the 5′SS, BP, and 3′SS are indicated. For most yeast introns, a stretch of Pyr, functions with the 3′SS YAG in definition of the 3′SS. Triangles denote the location of Prp8 cross-links observed in either mammalian (▴), or yeast (▵) systems. For all studies except those with an asterisk (*), the location of the cross-linked site is determined through the use of a site-specific photoreactive substitution or by RNase fingerprinting. (*) Approximated sites of cross-linking within an RNase T1 fragment.