DNA replication intermediates synthesized by lysates of dnaB, dnaG and dnaB dnaG mutants in vitro.

Isogenic dnaB, dnaG, and dnaB dnaG mutants were constructed and used as extracts in the cellophane-disc in vitro DNA replication system. The increased proportion of 5S DNA characteristics of the dnab extract and the lack of Okazaki piece synthesis characteristic of the dnaG extract were both apparent in analysis of the dnaB dnaG mutant extract reaction. A hypothetical scheme to explain these results and those of others is presented.