Crystal structure, mutational analysis and RNA-dependent ATPase activity of the yeast DEAD-box pre-mRNA splicing factor Prp28.

ABSTRACT: Yeast Prp28 is a DEAD-box pre-mRNA splicing factor implicated in displacing U1 snRNP from the 5' splice site. Here we report that the 588-aa Prp28 protein consists of a trypsin-sensitive 126-aa N-terminal segment (of which aa 1-89 are dispensable for Prp28 function in vivo) fused to a trypsin-resistant C-terminal catalytic domain. Purified recombinant Prp28 and Prp28-(127-588) have an intrinsic RNA-dependent ATPase activity, albeit with a low turnover number. The crystal structure of Prp28-(127-588) comprises two RecA-like domains splayed widely apart. AMPPNP•Mg2+ is engaged by the proximal domain, with proper and specific contacts from Phe194 and Gln201 (Q motif) to the adenine nucleobase. The triphosphate moiety of AMPPNP•Mg2+ is not poised for catalysis in the open domain conformation.

SUBMITTER: Jacewicz A 

PROVIDER: S-EPMC4227776 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature