Prp43p contains a processive helicase structural architecture with a specific regulatory domain

Area of Science:

• Molecular Biology
• Structural Biology
• Biochemistry

Background:

• The DEAH/RNA helicase A (RHA) family is crucial for RNA processing, including splicing and ribosome biogenesis.
• Yeast Prp43p is a DEAH/RHA helicase with dual roles in both splicing and ribosome biogenesis.

Purpose of the Study:

• To elucidate the structural architecture of yeast Prp43p.
• To investigate the role of its C-terminal domain in nucleic acid binding and protein interactions.
• To understand the regulatory mechanisms of Prp43p activity.

Main Methods:

• X-ray crystallography to determine the structure of yeast Prp43p.
• Site-directed mutagenesis to assess the function of the C-terminal domain.
• Biochemical assays to measure ATPase activity and RNA binding affinity.

Main Results:

• Prp43p exhibits a novel structure with homology to Ski2-like DNA helicases, possessing features of a processive helicase.
• The C-terminal domain contains an oligonucleotide/oligosaccharide-binding (OB)-fold that binds RNA and the G-patch domain of Pfa1p.
• Mutations or deletions in the C-terminal domain reduce RNA binding and ATPase activity.

Conclusions:

• The C-terminal domain of Prp43p is essential for its RNA binding and ATPase activity.
• This domain acts as a regulatory hub, interacting with both RNA and regulatory proteins like Pfa1p.
• The findings provide insights into the mechanism of DEAH/RHA helicases in cellular processes.