Genetic analysis reveals a role for the C terminus of the Saccharomyces cerevisiae GTPase Snu114 during spliceosome activation.

ABSTRACT: Snu114 is the only GTPase required for mRNA splicing. As a homolog of elongation factor G, it contains three domains (III-V) predicted to undergo a large rearrangement following GTP hydrolysis. To assess the functional importance of the domains of Snu114, we used random mutagenesis to create conditionally lethal alleles. We identified three main classes: (1) mutations that are predicted to affect GTP binding and hydrolysis, (2) mutations that are clustered in 10- to 20-amino-acid stretches in each of domains III-V, and (3) mutations that result in deletion of up to 70 amino acids from the C terminus. Representative mutations from each of these classes blocked the first step of splicing in vivo and in vitro. The growth defects caused by most alleles were synthetically exacerbated by mutatio

SUBMITTER: Brenner TJ 

PROVIDER: S-EPMC1451163 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature