The purified yeast pre-mRNA splicing factor PRP2 is an RNA-dependent NTPase.
Unlike autocatalyzed self-splicing reactions, nuclear pre-mRNA splicing requires transacting macromolecules and ATP. A protein encoded by the PRP2 gene of Saccharomyces cerevisiae is required, in conjunction with ATP, for the first cleavage-ligation reaction of pre-mRNA splicing. In this study, we have purified two forms of the PRP2 gene product with apparent molecular weights of 100 kDa and 92 kDa, from a yeast strain overproducing the protein. Both proteins were indistinguishable in their ability to complement extracts derived from a heat-sensitive prp2 mutant. Furthermore, we show that the PRP2 protein is capable of hydrolyzing nucleoside triphosphates in the presence of single-stranded RNAs such as poly(U). However, purified PRP2 by itself did not unwind double-stranded RNA substrates. The fact that an RNA-dependent NTPase activity is intrinsic to PRP2 may account for the ATP requirement in the first catalytic reaction of pre-mRNA splicing.
Kim
S H
SH
Department of Microbiology, University of Texas, Austin 78712-1095.
Smith
J
J
Claude
A
A
Lin
R J
RJ
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015153:Blotting, Western; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D053487:DEAD-box RNA Helicases; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D007700:Kinetics; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
D005656:Fungal Proteins; D012322:RNA Precursors; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C066490:PRP2 protein, S cerevisiae; C027900:RNA-dependent ATPase; D053487:DEAD-box RNA Helicases