Figure 7.

E-2e and E-2a correspond to the splicing factors Prp8 and Ncm, respectively. (A) Schematic of the D. melanogaster Prp8 protein. The prp8^2e1 and prp8^2e2 mutations alter highly conserved amino acid residues within the 3′ splice site fidelity region 3.2 (3.2). Also shown is a putative nuclear localization sequence (NLS), a putative RNA recognition motif (RRM), and an MPN domain—see text for details. Amino acid numbering is given for each Prp8 ortholog. Note that the A. thaliana genome contains two different genes that encode slightly different Prp8 proteins. (B) Schematic of the D. melanogaster Ncm protein and orthologs from different species. Domains shown are: MIF4G domain (solid boxes), MA3 domain (shaded boxes), RS domains (diagonal hatching), and poly-serine tract (stippled). The ncm^2a2 and ncm^2a1 mutations each create premature STOP codons at amino acid positions 301 and 768, respectively. The ncm^SH0931 P-element insertion (triangle) is located within the predicted C-terminal RS domain. Ncm orthologs from different species are shown with their percentage identity over a ∼500-amino-acid stretch between conserved YIPP and IGLG tetrapeptides in the central region of the D. melanogaster protein; amino acid sequences outside of this central sequence are far less conserved. Note that the Anopheles gambiae Ncm protein is predicted from a partial cDNA clone that is missing amino- and/or carboxy-terminal sequences. Abbreviations and accession numbers (Prp8/Ncm) are: D.m., D. melanogaster (NP_610735.1/NP_609877.2); A.g., A. gambiae (XP_308873.1/XP_317618.1); H.s., Homo sapiens (NP_006436.2/XP_034594.2); C.e., C. elegans (NP_498785.1/NP_496363.1); A.t., Arabidopsis thaliana (NP_178124.1 and NP_195589.2/NP_178208.1); S.p., S. pombe (NP_593861.1/Q9P6R9); and S.c., S. cerevisiae (NP_012035.1/NP_011794.1).