The structure of Sky1p reveals a novel mechanism for constitutive activity.

摘要: Sky1p is the only member of SR protein kinase (SRPK) family in Saccharomyces cerevisiae. SRPKs are constitutively active kinases that display remarkable substrate specificity and have been implicated RNA processing. Here we present three-dimensional structure a fully truncated Sky1p. Analysis structure-based functional studies reveal C-terminal tail, an unusual Glu residue located P+1 loop, unique mechanism for positioning helix alpha C act together to render active. We modeled peptide bound The complex combined with mutagenesis illustrate molecular basis recognition by this suggest which catalyze sequential phosphorylation reaction consecutive RS dipeptide repeats characteristic mammalian SRPK substrates.