SLU7 Splicing Factor Homolog (SLU7)

Splicing factors for step 2, such as PRP18 and SLU7, bring near and distant 3-prime splice sites into the active site of the spliceosome.The deduced 586-amino acid protein is 204 amino acids longer than yeast Slu7 and is 41% identical to the worm and Arabidopsis proteins.SLU7 contains a zinc knuckle, a motif found in several splicing factors. Western blot analysis showed expression of a 70-kD nuclear protein that associates with the spliceosome relatively late in the assembly process. The association of SLU7 with the spliceosome is coupled to the catalysis of step 1. Depletion of SLU7 resulted in the accumulation of novel intermediate C-type spliceosomal complexes that were blocked before step 2.