Abstract
Divalent beryllium increases misincorporation during polymerization of poly-d(A-T) by Micrococcusluteus DNA polymerase. The effect is associated with a strong inhibition of the 3′–5′ exonuclease (editing) activity of the enzyme by beryllium relative to the polymerase activity. Possible connections between these results and the toxicity of beryllium are discussed.