Functional interactions of Prp8 with both splice sites at the spliceosomal catalytic center.

ABSTRACT: A U5 snRNP protein, hPrp8, interacts closely with the GU dinucleotide at the 5' splice site (5'SS), forming a specific UV-inducible cross-link. To test if this physical contact between the 5'SS and the carboxy-terminal region of Prp8 reflects a functional recognition of the 5'SS during spliceosome assembly, we mutagenized the corresponding region of yeast Prp8 and screened the resulting mutants for suppression of 5'SS mutations in vivo. All of the isolated prp8 alleles not only suppress 5'SS but also 3'SS mutations, affecting the second catalytic step. Suppression of the 5'SS mutations by prp8 alleles was also tested in the presence of U1-7U snRNA, a predicted suppressor of the U+2A mutation. As expected, U1-7U efficiently suppresses prespliceosome formation, and the first, but not the sec

SUBMITTER: Siatecka M 

PROVIDER: S-EPMC316927 | biostudies-literature | 1999 Aug

REPOSITORIES: biostudies-literature