Fission yeast Mcm10p contains primase activity

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Mcm10p is a conserved protein vital for DNA replication in eukaryotes.
• The biochemical functions of Mcm10p have remained largely uncharacterized.

Purpose of the Study:

• To investigate the biochemical properties of Schizosaccharomyces pombe Mcm10p.
• To determine if Mcm10p possesses enzymatic activity related to DNA replication.

Main Methods:

• In vitro biochemical assays to assess Mcm10p's enzymatic activity.
• Oligoribonucleotide synthesis experiments using Mcm10p and DNA polymerase I.
• Site-directed mutagenesis of a conserved C-terminal motif in Mcm10p.

Main Results:

• Schizosaccharomyces pombe Mcm10p exhibits primase activity, synthesizing short RNA primers.
• Mcm10p preferentially initiates RNA synthesis on a dT template.
• A point mutation in the conserved C-terminal motif abolished in vitro primer synthesis and in vivo growth.

Conclusions:

• Mcm10p functions as a primase, an enzyme critical for initiating DNA synthesis.
• The primase activity of Mcm10p is essential for the viability of fission yeast cells.
• The C-terminal region of Mcm10p is important for its primase function.