DNA synthesis in vivo in Bacillus subtilis

DNA polymerase III is the enzyme responsible for deoxynucleotide addition to nascent DNA fragments in Bacillus subtilis protoplasts. Nascent single-stranded fragments separated from bulk DNA by hydroxyapatite chromatography cannot self-anneal. Partial inhibition of DNA polymerase III by 6-(hydroxyphenylazo)-uracil, a specific inhibitor, slows the rate of nascent fragment synthesis but has no effect on final size. Neither DNA polymerase I nor II can elongate nascent fragments in protoplasts when DNA polymerase III is completely inhibited. © 1976.