Synthesis by the DNA primase of Drosophila melanogaster of a primer with a unique chain length.

Abstract

The primase associated with the DNA polymerase .alpha. from embryos of D. melanogaster catalyzes the synthesis of ribo-oligonucleotide primers on single-stranded M13 DNA or polydeoxythymidylate templates, which can be elongated by DNA polymerase action. The primers synthesized in a coupled primase-DNA polymerase .alpha. reaction with an M13 DNA template are of a unique size (15 residues); those synthesized with poly(dT) range from 8-15 nucleotides. Primer synthesis is initiated at multiple but nonrandom sites. Like the DNA primase of Escherichia coli and the comparable activity in intact nuclei of polyoma-infected mouse cells, the DNA primase of D. melanogaster can substitute deoxynucleotides for ribonucleotides during primer synthesis.