Mutations in conserved yeast DNA primase domains impair DNA replication in vivo

S Francesconi1, M P Longhese, A Piseri

  • 1Dipartimento di Genetica e di Biologia dei Microrganismi, Milano, Italy.

Insights

This study demonstrates the essential role of eukaryotic DNA primase in DNA replication. Conditional mutations in yeast DNA primase genes confirmed its necessity for synthesizing high molecular weight DNA products in vivo.

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • Eukaryotic DNA primase is crucial for initiating DNA replication.
  • Understanding its in vivo function is essential for comprehending replication fidelity and mechanisms.

Purpose of the Study:

  • To investigate the in vivo role of eukaryotic DNA primase.
  • To generate and characterize conditional and lethal mutations in yeast DNA primase subunits.

Main Methods:

  • Random in vitro mutagenesis of PR11 and PR12 genes encoding yeast DNA primase subunits.
  • Replacement of wild-type genes with conditional alleles (pri1 and pri2).
  • Analysis of DNA synthesis and product formation at restrictive temperatures.

Main Results:

  • Conditional yeast strains exhibited altered DNA synthesis upon temperature shift.
  • Reduced ability to synthesize high molecular weight DNA products was observed.
  • Nucleotide-level mapping revealed conserved amino acid residue changes in mutated subunits.

Conclusions:

  • This study provides in vivo evidence for the essential function of DNA primase in eukaryotic DNA replication.
  • Mutations affecting conserved amino acid residues highlight critical functional domains of DNA primase.

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