Characterization of the NTPase, RNA-binding, and RNA helicase activities of the DEAH-box splicing factor Prp22. Academic Article uri icon

Overview

abstract

  • The DEAH protein Prp22 is important for the second transesterification step of pre-mRNA splicing, and it is essential for releasing mature mRNA from the spliceosome. Recombinant Prp22 has RNA-stimulated ATPase and ATP-dependent unwinding activities, which are crucial for the mRNA release step. In this study, we characterize the RNA-binding, NTP hydrolysis, and RNA unwinding functions of Prp22. Using nitrocellulose filter binding assays, we determined that the apparent affinity of Prp22 is approximately 20-fold greater for single-stranded RNA than for single-stranded DNA or duplex nucleic acids. Inclusion of hydrolyzable ATP in binding reactions increased the apparent K(D) for RNA by 3-4-fold. The Prp22-RNA interaction is influenced by the length of the RNA chain, and the apparent K(D) values for poly(A)(40) and poly(A)(10) are 17 and 140 nM, respectively. RNA-stimulated ATP hydrolysis is similarly affected by chain length, and optimal activity requires RNA oligomers of >or=20 nt. We show that Prp22 can hydrolyze all common NTPs and dNTPs with comparable efficiencies and that Prp22 unwinds RNA duplexes with 3' to 5' directionality.

publication date

  • July 19, 2005

Research

keywords

  • Adenosine Triphosphatases
  • DNA Helicases
  • Nucleoside-Triphosphatase
  • RNA Helicases
  • RNA, Fungal
  • Saccharomyces cerevisiae Proteins
  • Spliceosomes

Identity

Scopus Document Identifier

  • 22244444183

Digital Object Identifier (DOI)

  • 10.1021/bi050407m

PubMed ID

  • 16008364

Additional Document Info

volume

  • 44

issue

  • 28